Commit Graph

13 Commits

Author SHA1 Message Date
ChenLiang 1b826f2778 xbzrle: rebuild the cache_is_cached function
Rebuild the cache_is_cached function by cache_get_by_addr. And
drops the asserts because the caller is also asserting the same
thing.

Signed-off-by: ChenLiang <chenliang88@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2015-01-15 17:49:43 +05:30
ChenLiang 27af7d6ea5 xbzrle: optimize XBZRLE to decrease the cache misses
Avoid hot pages being replaced by others to remarkably decrease cache
misses

Sample results with the test program which quote from xbzrle.txt ran in
vm:(migrate bandwidth:1GE and xbzrle cache size 8MB)

the test program:

include <stdlib.h>
include <stdio.h>
int main()
 {
        char *buf = (char *) calloc(4096, 4096);
        while (1) {
            int i;
            for (i = 0; i < 4096 * 4; i++) {
                buf[i * 4096 / 4]++;
            }
            printf(".");
        }
 }

before this patch:
virsh qemu-monitor-command test_vm '{"execute": "query-migrate"}'
{"return":{"expected-downtime":1020,"xbzrle-cache":{"bytes":1108284,
"cache-size":8388608,"cache-miss-rate":0.987013,"pages":18297,"overflow":8,
"cache-miss":1228737},"status":"active","setup-time":10,"total-time":52398,
"ram":{"total":12466991104,"remaining":1695744,"mbps":935.559472,
"transferred":5780760580,"dirty-sync-counter":271,"duplicate":2878530,
"dirty-pages-rate":29130,"skipped":0,"normal-bytes":5748592640,
"normal":1403465}},"id":"libvirt-706"}

18k pages sent compressed in 52 seconds.
cache-miss-rate is 98.7%, totally miss.

after optimizing:
virsh qemu-monitor-command test_vm '{"execute": "query-migrate"}'
{"return":{"expected-downtime":2054,"xbzrle-cache":{"bytes":5066763,
"cache-size":8388608,"cache-miss-rate":0.485924,"pages":194823,"overflow":0,
"cache-miss":210653},"status":"active","setup-time":11,"total-time":18729,
"ram":{"total":12466991104,"remaining":3895296,"mbps":937.663549,
"transferred":1615042219,"dirty-sync-counter":98,"duplicate":2869840,
"dirty-pages-rate":58781,"skipped":0,"normal-bytes":1588404224,
"normal":387794}},"id":"libvirt-266"}

194k pages sent compressed in 18 seconds.
The value of cache-miss-rate decrease to 48.59%.

Signed-off-by: ChenLiang <chenliang88@huawei.com>
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
2015-01-15 17:49:43 +05:30
Chen Gang 4380be0e99 migration: Plug memory leak in migrate-set-cache-size command
We call g_free() after cache_fini() in migration_end(), but we don't
call it after cache_fini() in xbzrle_cache_resize(), leaking the
memory.

cache_init() and cache_fini() are a pair.  Since cache_init()
allocates the cache, let cache_fini() free it.  This plugs the leak.

Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2014-06-10 19:54:43 +04:00
Dr. David Alan Gilbert 6d3cb1f970 Fix two XBZRLE corruption issues
Push zero'd pages into the XBZRLE cache
    A page that was cached by XBZRLE, zero'd and then XBZRLE'd again
    was being compared against a stale cache value

Don't use 'qemu_put_buffer_async' to put pages from the XBZRLE cache
    Since the cache might change before the data hits the wire

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2014-02-25 14:30:28 +01:00
Orit Wasserman 89db9987c0 Don't abort on memory allocation error
It is better to fail migration in case of failure to
allocate new cache item

Signed-off-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2014-02-04 16:50:37 +01:00
Orit Wasserman a17b2fd358 Don't abort on out of memory when creating page cache
Signed-off-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2014-02-04 16:50:22 +01:00
Michael Tokarev 997aba8e25 remove some double-includes
Some source files #include the same header more than
once for no good reason.  Remove second #includes in
such cases.

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
2013-05-18 16:35:12 +04:00
Peter Lieven ee0b44aa9d page_cache: dup memory on insert
The page cache frees all data on finish, on resize and
if there is collision on insert. So it should be the caches
responsibility to dup the data that is stored in the cache.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Orit Wasserman <owasserm@redhat.com>

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:03 +01:00
Peter Lieven 32a1c08b60 page_cache: fix memory leak
XBZRLE encoded migration introduced a MRU page cache
meachnism. Unfortunately, cached items where never freed in
case of a collision in the page cache on cache_insert().

This lead to out of memory conditions during XBZRLE migration
if the page cache was small and there where a lot of collisions
in the cache.

Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Orit Wasserman <owasserm@redhat.com>

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:03 +01:00
Orit Wasserman a0ee2031db Fix cache_resize to keep old entry age
Instead of using cache_insert do the update itself

Signed-off-by: Orit Wasserman <owasserm@redhat.com>

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:03 +01:00
Orit Wasserman 0db65d624e Fix page_cache leak in cache_resize
Signed-off-by: Orit Wasserman <owasserm@redhat.com>

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Juan Quintela <quintela@redhat.com>
2013-03-11 13:32:03 +01:00
Paolo Bonzini caf71f86a3 migration: move include files to include/migration/
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19 08:31:32 +01:00
Orit Wasserman 9fb26641ab Add cache handling functions
Add MRU page cache mechanism.
The page are accessed by their address.

Signed-off-by: Benoit Hudzia <benoit.hudzia@sap.com>
Signed-off-by: Petter Svard <petters@cs.umu.se>
Signed-off-by: Aidan Shribman <aidan.shribman@sap.com>
Signed-off-by: Orit Wasserman <owasserm@redhat.com>

Reviewed-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2012-08-08 13:51:12 +02:00