linux/fs/mbcache.c

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mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/list_bl.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/workqueue.h>
#include <linux/mbcache.h>
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
/*
* Mbcache is a simple key-value store. Keys need not be unique, however
* key-value pairs are expected to be unique (we use this fact in
* mb_cache_entry_delete()).
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
*
* Ext2 and ext4 use this cache for deduplication of extended attribute blocks.
* Ext4 also uses it for deduplication of xattr values stored in inodes.
* They use hash of data as a key and provide a value that may represent a
* block or inode number. That's why keys need not be unique (hash of different
* data may be the same). However user provided value always uniquely
* identifies a cache entry.
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
*
* We provide functions for creation and removal of entries, search by key,
* and a special "delete entry with given key-value pair" operation. Fixed
* size hash table is used for fast key lookups.
*/
struct mb_cache {
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
/* Hash table of entries */
struct hlist_bl_head *c_hash;
/* log2 of hash table size */
int c_bucket_bits;
/* Maximum entries in cache to avoid degrading hash too much */
unsigned long c_max_entries;
/* Protects c_list, c_entry_count */
spinlock_t c_list_lock;
struct list_head c_list;
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
/* Number of entries in cache */
unsigned long c_entry_count;
struct shrinker c_shrink;
/* Work for shrinking when the cache has too many entries */
struct work_struct c_shrink_work;
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
};
static struct kmem_cache *mb_entry_cache;
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
static unsigned long mb_cache_shrink(struct mb_cache *cache,
unsigned long nr_to_scan);
static inline struct hlist_bl_head *mb_cache_entry_head(struct mb_cache *cache,
u32 key)
{
return &cache->c_hash[hash_32(key, cache->c_bucket_bits)];
}
/*
* Number of entries to reclaim synchronously when there are too many entries
* in cache
*/
#define SYNC_SHRINK_BATCH 64
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
/*
* mb_cache_entry_create - create entry in cache
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
* @cache - cache where the entry should be created
* @mask - gfp mask with which the entry should be allocated
* @key - key of the entry
* @value - value of the entry
* @reusable - is the entry reusable by others?
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
*
* Creates entry in @cache with key @key and value @value. The function returns
* -EBUSY if entry with the same key and value already exists in cache.
* Otherwise 0 is returned.
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
*/
int mb_cache_entry_create(struct mb_cache *cache, gfp_t mask, u32 key,
u64 value, bool reusable)
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
{
struct mb_cache_entry *entry, *dup;
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
struct hlist_bl_node *dup_node;
struct hlist_bl_head *head;
/* Schedule background reclaim if there are too many entries */
if (cache->c_entry_count >= cache->c_max_entries)
schedule_work(&cache->c_shrink_work);
/* Do some sync reclaim if background reclaim cannot keep up */
if (cache->c_entry_count >= 2*cache->c_max_entries)
mb_cache_shrink(cache, SYNC_SHRINK_BATCH);
entry = kmem_cache_alloc(mb_entry_cache, mask);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
if (!entry)
return -ENOMEM;
INIT_LIST_HEAD(&entry->e_list);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
/* One ref for hash, one ref returned */
atomic_set(&entry->e_refcnt, 1);
entry->e_key = key;
entry->e_value = value;
entry->e_reusable = reusable;
mbcache: initialize entry->e_referenced in mb_cache_entry_create() KMSAN reported use of uninitialized |entry->e_referenced| in a condition in mb_cache_shrink(): ================================================================== BUG: KMSAN: use of uninitialized memory in mb_cache_shrink+0x3b4/0xc50 fs/mbcache.c:287 CPU: 2 PID: 816 Comm: kswapd1 Not tainted 4.11.0-rc5+ #2877 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x172/0x1c0 lib/dump_stack.c:52 kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:927 __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:469 mb_cache_shrink+0x3b4/0xc50 fs/mbcache.c:287 mb_cache_scan+0x67/0x80 fs/mbcache.c:321 do_shrink_slab mm/vmscan.c:397 [inline] shrink_slab+0xc3d/0x12d0 mm/vmscan.c:500 shrink_node+0x208f/0x2fd0 mm/vmscan.c:2603 kswapd_shrink_node mm/vmscan.c:3172 [inline] balance_pgdat mm/vmscan.c:3289 [inline] kswapd+0x160f/0x2850 mm/vmscan.c:3478 kthread+0x46c/0x5f0 kernel/kthread.c:230 ret_from_fork+0x29/0x40 arch/x86/entry/entry_64.S:430 chained origin: save_stack_trace+0x37/0x40 arch/x86/kernel/stacktrace.c:59 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:302 [inline] kmsan_save_stack mm/kmsan/kmsan.c:317 [inline] kmsan_internal_chain_origin+0x12a/0x1f0 mm/kmsan/kmsan.c:547 __msan_store_shadow_origin_1+0xac/0x110 mm/kmsan/kmsan_instr.c:257 mb_cache_entry_create+0x3b3/0xc60 fs/mbcache.c:95 ext4_xattr_cache_insert fs/ext4/xattr.c:1647 [inline] ext4_xattr_block_set+0x4c82/0x5530 fs/ext4/xattr.c:1022 ext4_xattr_set_handle+0x1332/0x20a0 fs/ext4/xattr.c:1252 ext4_xattr_set+0x4d2/0x680 fs/ext4/xattr.c:1306 ext4_xattr_trusted_set+0x8d/0xa0 fs/ext4/xattr_trusted.c:36 __vfs_setxattr+0x703/0x790 fs/xattr.c:149 __vfs_setxattr_noperm+0x27a/0x6f0 fs/xattr.c:180 vfs_setxattr fs/xattr.c:223 [inline] setxattr+0x6ae/0x790 fs/xattr.c:449 path_setxattr+0x1eb/0x380 fs/xattr.c:468 SYSC_lsetxattr+0x8d/0xb0 fs/xattr.c:490 SyS_lsetxattr+0x77/0xa0 fs/xattr.c:486 entry_SYSCALL_64_fastpath+0x13/0x94 origin: save_stack_trace+0x37/0x40 arch/x86/kernel/stacktrace.c:59 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:302 [inline] kmsan_internal_poison_shadow+0xb1/0x1a0 mm/kmsan/kmsan.c:198 kmsan_kmalloc+0x7f/0xe0 mm/kmsan/kmsan.c:337 kmem_cache_alloc+0x1c2/0x1e0 mm/slub.c:2766 mb_cache_entry_create+0x283/0xc60 fs/mbcache.c:86 ext4_xattr_cache_insert fs/ext4/xattr.c:1647 [inline] ext4_xattr_block_set+0x4c82/0x5530 fs/ext4/xattr.c:1022 ext4_xattr_set_handle+0x1332/0x20a0 fs/ext4/xattr.c:1252 ext4_xattr_set+0x4d2/0x680 fs/ext4/xattr.c:1306 ext4_xattr_trusted_set+0x8d/0xa0 fs/ext4/xattr_trusted.c:36 __vfs_setxattr+0x703/0x790 fs/xattr.c:149 __vfs_setxattr_noperm+0x27a/0x6f0 fs/xattr.c:180 vfs_setxattr fs/xattr.c:223 [inline] setxattr+0x6ae/0x790 fs/xattr.c:449 path_setxattr+0x1eb/0x380 fs/xattr.c:468 SYSC_lsetxattr+0x8d/0xb0 fs/xattr.c:490 SyS_lsetxattr+0x77/0xa0 fs/xattr.c:486 entry_SYSCALL_64_fastpath+0x13/0x94 ================================================================== Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: stable@vger.kernel.org # v4.6
2018-01-07 22:22:35 +01:00
entry->e_referenced = 0;
head = mb_cache_entry_head(cache, key);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
hlist_bl_lock(head);
hlist_bl_for_each_entry(dup, dup_node, head, e_hash_list) {
if (dup->e_key == key && dup->e_value == value) {
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
hlist_bl_unlock(head);
kmem_cache_free(mb_entry_cache, entry);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
return -EBUSY;
}
}
hlist_bl_add_head(&entry->e_hash_list, head);
hlist_bl_unlock(head);
spin_lock(&cache->c_list_lock);
list_add_tail(&entry->e_list, &cache->c_list);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
/* Grab ref for LRU list */
atomic_inc(&entry->e_refcnt);
cache->c_entry_count++;
spin_unlock(&cache->c_list_lock);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
return 0;
}
EXPORT_SYMBOL(mb_cache_entry_create);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
void __mb_cache_entry_free(struct mb_cache_entry *entry)
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
{
kmem_cache_free(mb_entry_cache, entry);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
}
EXPORT_SYMBOL(__mb_cache_entry_free);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
static struct mb_cache_entry *__entry_find(struct mb_cache *cache,
struct mb_cache_entry *entry,
u32 key)
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
{
struct mb_cache_entry *old_entry = entry;
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
struct hlist_bl_node *node;
struct hlist_bl_head *head;
head = mb_cache_entry_head(cache, key);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
hlist_bl_lock(head);
if (entry && !hlist_bl_unhashed(&entry->e_hash_list))
node = entry->e_hash_list.next;
else
node = hlist_bl_first(head);
while (node) {
entry = hlist_bl_entry(node, struct mb_cache_entry,
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
e_hash_list);
if (entry->e_key == key && entry->e_reusable) {
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
atomic_inc(&entry->e_refcnt);
goto out;
}
node = node->next;
}
entry = NULL;
out:
hlist_bl_unlock(head);
if (old_entry)
mb_cache_entry_put(cache, old_entry);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
return entry;
}
/*
* mb_cache_entry_find_first - find the first reusable entry with the given key
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
* @cache: cache where we should search
* @key: key to look for
*
* Search in @cache for a reusable entry with key @key. Grabs reference to the
* first reusable entry found and returns the entry.
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
*/
struct mb_cache_entry *mb_cache_entry_find_first(struct mb_cache *cache,
u32 key)
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
{
return __entry_find(cache, NULL, key);
}
EXPORT_SYMBOL(mb_cache_entry_find_first);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
/*
* mb_cache_entry_find_next - find next reusable entry with the same key
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
* @cache: cache where we should search
* @entry: entry to start search from
*
* Finds next reusable entry in the hash chain which has the same key as @entry.
* If @entry is unhashed (which can happen when deletion of entry races with the
* search), finds the first reusable entry in the hash chain. The function drops
* reference to @entry and returns with a reference to the found entry.
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
*/
struct mb_cache_entry *mb_cache_entry_find_next(struct mb_cache *cache,
struct mb_cache_entry *entry)
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
{
return __entry_find(cache, entry, entry->e_key);
}
EXPORT_SYMBOL(mb_cache_entry_find_next);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
/*
* mb_cache_entry_get - get a cache entry by value (and key)
* @cache - cache we work with
* @key - key
* @value - value
*/
struct mb_cache_entry *mb_cache_entry_get(struct mb_cache *cache, u32 key,
u64 value)
{
struct hlist_bl_node *node;
struct hlist_bl_head *head;
struct mb_cache_entry *entry;
head = mb_cache_entry_head(cache, key);
hlist_bl_lock(head);
hlist_bl_for_each_entry(entry, node, head, e_hash_list) {
if (entry->e_key == key && entry->e_value == value) {
atomic_inc(&entry->e_refcnt);
goto out;
}
}
entry = NULL;
out:
hlist_bl_unlock(head);
return entry;
}
EXPORT_SYMBOL(mb_cache_entry_get);
/* mb_cache_entry_delete - remove a cache entry
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
* @cache - cache we work with
* @key - key
* @value - value
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
*
* Remove entry from cache @cache with key @key and value @value.
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
*/
void mb_cache_entry_delete(struct mb_cache *cache, u32 key, u64 value)
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
{
struct hlist_bl_node *node;
struct hlist_bl_head *head;
struct mb_cache_entry *entry;
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
head = mb_cache_entry_head(cache, key);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
hlist_bl_lock(head);
hlist_bl_for_each_entry(entry, node, head, e_hash_list) {
if (entry->e_key == key && entry->e_value == value) {
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
/* We keep hash list reference to keep entry alive */
hlist_bl_del_init(&entry->e_hash_list);
hlist_bl_unlock(head);
spin_lock(&cache->c_list_lock);
if (!list_empty(&entry->e_list)) {
list_del_init(&entry->e_list);
if (!WARN_ONCE(cache->c_entry_count == 0,
"mbcache: attempt to decrement c_entry_count past zero"))
cache->c_entry_count--;
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
atomic_dec(&entry->e_refcnt);
}
spin_unlock(&cache->c_list_lock);
mb_cache_entry_put(cache, entry);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
return;
}
}
hlist_bl_unlock(head);
}
EXPORT_SYMBOL(mb_cache_entry_delete);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
/* mb_cache_entry_touch - cache entry got used
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
* @cache - cache the entry belongs to
* @entry - entry that got used
*
* Marks entry as used to give hit higher chances of surviving in cache.
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
*/
void mb_cache_entry_touch(struct mb_cache *cache,
struct mb_cache_entry *entry)
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
{
entry->e_referenced = 1;
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
}
EXPORT_SYMBOL(mb_cache_entry_touch);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
static unsigned long mb_cache_count(struct shrinker *shrink,
struct shrink_control *sc)
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
{
struct mb_cache *cache = container_of(shrink, struct mb_cache,
c_shrink);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
return cache->c_entry_count;
}
/* Shrink number of entries in cache */
static unsigned long mb_cache_shrink(struct mb_cache *cache,
unsigned long nr_to_scan)
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
{
struct mb_cache_entry *entry;
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
struct hlist_bl_head *head;
unsigned long shrunk = 0;
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
spin_lock(&cache->c_list_lock);
while (nr_to_scan-- && !list_empty(&cache->c_list)) {
entry = list_first_entry(&cache->c_list,
struct mb_cache_entry, e_list);
if (entry->e_referenced) {
entry->e_referenced = 0;
list_move_tail(&entry->e_list, &cache->c_list);
continue;
}
list_del_init(&entry->e_list);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
cache->c_entry_count--;
/*
* We keep LRU list reference so that entry doesn't go away
* from under us.
*/
spin_unlock(&cache->c_list_lock);
head = mb_cache_entry_head(cache, entry->e_key);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
hlist_bl_lock(head);
if (!hlist_bl_unhashed(&entry->e_hash_list)) {
hlist_bl_del_init(&entry->e_hash_list);
atomic_dec(&entry->e_refcnt);
}
hlist_bl_unlock(head);
if (mb_cache_entry_put(cache, entry))
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
shrunk++;
cond_resched();
spin_lock(&cache->c_list_lock);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
}
spin_unlock(&cache->c_list_lock);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
return shrunk;
}
static unsigned long mb_cache_scan(struct shrinker *shrink,
struct shrink_control *sc)
{
struct mb_cache *cache = container_of(shrink, struct mb_cache,
c_shrink);
return mb_cache_shrink(cache, sc->nr_to_scan);
}
/* We shrink 1/X of the cache when we have too many entries in it */
#define SHRINK_DIVISOR 16
static void mb_cache_shrink_worker(struct work_struct *work)
{
struct mb_cache *cache = container_of(work, struct mb_cache,
c_shrink_work);
mb_cache_shrink(cache, cache->c_max_entries / SHRINK_DIVISOR);
}
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
/*
* mb_cache_create - create cache
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
* @bucket_bits: log2 of the hash table size
*
* Create cache for keys with 2^bucket_bits hash entries.
*/
struct mb_cache *mb_cache_create(int bucket_bits)
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
{
struct mb_cache *cache;
unsigned long bucket_count = 1UL << bucket_bits;
unsigned long i;
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
cache = kzalloc(sizeof(struct mb_cache), GFP_KERNEL);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
if (!cache)
goto err_out;
cache->c_bucket_bits = bucket_bits;
cache->c_max_entries = bucket_count << 4;
INIT_LIST_HEAD(&cache->c_list);
spin_lock_init(&cache->c_list_lock);
treewide: kmalloc() -> kmalloc_array() The kmalloc() function has a 2-factor argument form, kmalloc_array(). This patch replaces cases of: kmalloc(a * b, gfp) with: kmalloc_array(a * b, gfp) as well as handling cases of: kmalloc(a * b * c, gfp) with: kmalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kmalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kmalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The tools/ directory was manually excluded, since it has its own implementation of kmalloc(). The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(char) * COUNT + COUNT , ...) | kmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kmalloc + kmalloc_array ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kmalloc(C1 * C2 * C3, ...) | kmalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kmalloc(sizeof(THING) * C2, ...) | kmalloc(sizeof(TYPE) * C2, ...) | kmalloc(C1 * C2 * C3, ...) | kmalloc(C1 * C2, ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - (E1) * E2 + E1, E2 , ...) | - kmalloc + kmalloc_array ( - (E1) * (E2) + E1, E2 , ...) | - kmalloc + kmalloc_array ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-12 22:55:00 +02:00
cache->c_hash = kmalloc_array(bucket_count,
sizeof(struct hlist_bl_head),
GFP_KERNEL);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
if (!cache->c_hash) {
kfree(cache);
goto err_out;
}
for (i = 0; i < bucket_count; i++)
INIT_HLIST_BL_HEAD(&cache->c_hash[i]);
cache->c_shrink.count_objects = mb_cache_count;
cache->c_shrink.scan_objects = mb_cache_scan;
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
cache->c_shrink.seeks = DEFAULT_SEEKS;
if (register_shrinker(&cache->c_shrink)) {
kfree(cache->c_hash);
kfree(cache);
goto err_out;
}
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
INIT_WORK(&cache->c_shrink_work, mb_cache_shrink_worker);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
return cache;
err_out:
return NULL;
}
EXPORT_SYMBOL(mb_cache_create);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
/*
* mb_cache_destroy - destroy cache
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
* @cache: the cache to destroy
*
* Free all entries in cache and cache itself. Caller must make sure nobody
* (except shrinker) can reach @cache when calling this.
*/
void mb_cache_destroy(struct mb_cache *cache)
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
{
struct mb_cache_entry *entry, *next;
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
unregister_shrinker(&cache->c_shrink);
/*
* We don't bother with any locking. Cache must not be used at this
* point.
*/
list_for_each_entry_safe(entry, next, &cache->c_list, e_list) {
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
if (!hlist_bl_unhashed(&entry->e_hash_list)) {
hlist_bl_del_init(&entry->e_hash_list);
atomic_dec(&entry->e_refcnt);
} else
WARN_ON(1);
list_del(&entry->e_list);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
WARN_ON(atomic_read(&entry->e_refcnt) != 1);
mb_cache_entry_put(cache, entry);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
}
kfree(cache->c_hash);
kfree(cache);
}
EXPORT_SYMBOL(mb_cache_destroy);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
static int __init mbcache_init(void)
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
{
mb_entry_cache = kmem_cache_create("mbcache",
sizeof(struct mb_cache_entry), 0,
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD, NULL);
if (!mb_entry_cache)
return -ENOMEM;
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
return 0;
}
static void __exit mbcache_exit(void)
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
{
kmem_cache_destroy(mb_entry_cache);
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
}
module_init(mbcache_init)
module_exit(mbcache_exit)
mbcache2: reimplement mbcache Original mbcache was designed to have more features than what ext? filesystems ended up using. It supported entry being in more hashes, it had a home-grown rwlocking of each entry, and one cache could cache entries from multiple filesystems. This genericity also resulted in more complex locking, larger cache entries, and generally more code complexity. This is reimplementation of the mbcache functionality to exactly fit the purpose ext? filesystems use it for. Cache entries are now considerably smaller (7 instead of 13 longs), the code is considerably smaller as well (414 vs 913 lines of code), and IMO also simpler. The new code is also much more lightweight. I have measured the speed using artificial xattr-bench benchmark, which spawns P processes, each process sets xattr for F different files, and the value of xattr is randomly chosen from a pool of V values. Averages of runtimes for 5 runs for various combinations of parameters are below. The first value in each cell is old mbache, the second value is the new mbcache. V=10 F\P 1 2 4 8 16 32 64 10 0.158,0.157 0.208,0.196 0.500,0.277 0.798,0.400 3.258,0.584 13.807,1.047 61.339,2.803 100 0.172,0.167 0.279,0.222 0.520,0.275 0.825,0.341 2.981,0.505 12.022,1.202 44.641,2.943 1000 0.185,0.174 0.297,0.239 0.445,0.283 0.767,0.340 2.329,0.480 6.342,1.198 16.440,3.888 V=100 F\P 1 2 4 8 16 32 64 10 0.162,0.153 0.200,0.186 0.362,0.257 0.671,0.496 1.433,0.943 3.801,1.345 7.938,2.501 100 0.153,0.160 0.221,0.199 0.404,0.264 0.945,0.379 1.556,0.485 3.761,1.156 7.901,2.484 1000 0.215,0.191 0.303,0.246 0.471,0.288 0.960,0.347 1.647,0.479 3.916,1.176 8.058,3.160 V=1000 F\P 1 2 4 8 16 32 64 10 0.151,0.129 0.210,0.163 0.326,0.245 0.685,0.521 1.284,0.859 3.087,2.251 6.451,4.801 100 0.154,0.153 0.211,0.191 0.276,0.282 0.687,0.506 1.202,0.877 3.259,1.954 8.738,2.887 1000 0.145,0.179 0.202,0.222 0.449,0.319 0.899,0.333 1.577,0.524 4.221,1.240 9.782,3.579 V=10000 F\P 1 2 4 8 16 32 64 10 0.161,0.154 0.198,0.190 0.296,0.256 0.662,0.480 1.192,0.818 2.989,2.200 6.362,4.746 100 0.176,0.174 0.236,0.203 0.326,0.255 0.696,0.511 1.183,0.855 4.205,3.444 19.510,17.760 1000 0.199,0.183 0.240,0.227 1.159,1.014 2.286,2.154 6.023,6.039 ---,10.933 ---,36.620 V=100000 F\P 1 2 4 8 16 32 64 10 0.171,0.162 0.204,0.198 0.285,0.230 0.692,0.500 1.225,0.881 2.990,2.243 6.379,4.771 100 0.151,0.171 0.220,0.210 0.295,0.255 0.720,0.518 1.226,0.844 3.423,2.831 19.234,17.544 1000 0.192,0.189 0.249,0.225 1.162,1.043 2.257,2.093 5.853,4.997 ---,10.399 ---,32.198 We see that the new code is faster in pretty much all the cases and starting from 4 processes there are significant gains with the new code resulting in upto 20-times shorter runtimes. Also for large numbers of cached entries all values for the old code could not be measured as the kernel started hitting softlockups and died before the test completed. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-22 17:49:09 +01:00
MODULE_AUTHOR("Jan Kara <jack@suse.cz>");
MODULE_DESCRIPTION("Meta block cache (for extended attributes)");
MODULE_LICENSE("GPL");