linux/lib
Ming Lei e6fc464987 blk-mq: avoid starving tag allocation after allocating process migrates
When the allocation process is scheduled back and the mapped hw queue is
changed, fake one extra wake up on previous queue for compensating wake
up miss, so other allocations on the previous queue won't be starved.

This patch fixes one request allocation hang issue, which can be
triggered easily in case of very low nr_request.

The race is as follows:

1) 2 hw queues, nr_requests are 2, and wake_batch is one

2) there are 3 waiters on hw queue 0

3) two in-flight requests in hw queue 0 are completed, and only two
   waiters of 3 are waken up because of wake_batch, but both the two
   waiters can be scheduled to another CPU and cause to switch to hw
   queue 1

4) then the 3rd waiter will wait for ever, since no in-flight request
   is in hw queue 0 any more.

5) this patch fixes it by the fake wakeup when waiter is scheduled to
   another hw queue

Cc: <stable@vger.kernel.org>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>

Modified commit message to make it clearer, and make it apply on
top of the 4.18 branch.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-05-24 11:00:39 -06:00
..
842
fonts
lz4
lzo
mpi
raid6 powerpc updates for 4.17 2018-04-07 12:08:19 -07:00
reed_solomon
xz
zlib_deflate
zlib_inflate
zstd lib: zstd: clean up Makefile for simpler composite object handling 2018-03-26 02:01:27 +09:00
.gitignore
Kconfig lib: Add generic PIO mapping method 2018-03-21 17:18:34 -05:00
Kconfig.debug lib/Kconfig.debug: Debug Lockups and Hangs: keep SOFTLOCKUP options together 2018-04-11 10:28:35 -07:00
Kconfig.kasan kasan: rework Kconfig settings 2018-02-06 18:32:47 -08:00
Kconfig.kgdb
Kconfig.ubsan lib: add testing module for UBSAN 2018-04-11 10:28:35 -07:00
Makefile lib: add testing module for UBSAN 2018-04-11 10:28:35 -07:00
argv_split.c
ashldi3.c
ashrdi3.c
asn1_decoder.c
assoc_array.c
atomic64.c
atomic64_test.c
audit.c
bcd.c
bch.c
bitmap.c lib: fix stall in __bitmap_parselist() 2018-04-05 21:36:21 -07:00
bitrev.c
bsearch.c
btree.c btree: avoid variable-length allocations 2018-03-14 16:55:29 -07:00
bucket_locks.c
bug.c lib/bug.c: exclude non-BUG/WARN exceptions from report_bug() 2018-03-09 16:40:01 -08:00
build_OID_registry
bust_spinlocks.c
chacha20.c
check_signature.c
checksum.c
clz_ctz.c
clz_tab.c
cmdline.c
cmpdi2.c
compat_audit.c
cordic.c
cpu_rmap.c
cpumask.c lib: optimize cpumask_next_and() 2018-02-06 18:32:44 -08:00
crc-ccitt.c
crc-itu-t.c
crc-t10dif.c
crc4.c
crc7.c
crc8.c
crc16.c
crc32.c
crc32defs.h
crc32test.c
ctype.c
debug_info.c
debug_locks.c
debugobjects.c debugobjects: Avoid another unused variable warning 2018-03-14 20:20:01 +01:00
dec_and_lock.c
decompress.c
decompress_bunzip2.c
decompress_inflate.c
decompress_unlz4.c
decompress_unlzma.c
decompress_unlzo.c
decompress_unxz.c
devres.c devres: combine function devm_ioremap* 2018-03-15 18:08:55 +01:00
digsig.c
div64.c
dma-debug.c dma-debug: fix memory leak in debug_dma_alloc_coherent 2018-02-22 15:02:33 -08:00
dma-direct.c dma-direct: don't retry allocation for no-op GFP_DMA 2018-04-23 14:43:27 +02:00
dma-virt.c
dump_stack.c printk: move dump stack related code to lib/dump_stack.c 2018-03-15 13:25:36 +01:00
dynamic_debug.c
dynamic_queue_limits.c
earlycpio.c
error-inject.c
errseq.c errseq: Always report a writeback error once 2018-04-27 08:51:26 -04:00
extable.c
fault-inject.c
fdt.c
fdt_empty_tree.c
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
find_bit.c lib: optimize cpumask_next_and() 2018-02-06 18:32:44 -08:00
find_bit_benchmark.c lib: optimize cpumask_next_and() 2018-02-06 18:32:44 -08:00
flex_array.c
flex_proportions.c
gcd.c
gen_crc32table.c
genalloc.c
glob.c
globtest.c
hexdump.c
hweight.c
idr.c idr: Fix handling of IDs above INT_MAX 2018-02-26 14:39:30 -05:00
inflate.c
int_sqrt.c lib: Add strongly typed 64bit int_sqrt 2018-02-04 10:17:21 +00:00
interval_tree.c
interval_tree_test.c
iomap.c
iomap_copy.c
iommu-common.c
iommu-helper.c
ioremap.c mm/vmalloc: add interfaces to free unmapped page table 2018-03-22 17:07:01 -07:00
iov_iter.c
irq_poll.c
irq_regs.c
is_single_threaded.c
jedec_ddr_data.c
kasprintf.c
kfifo.c kfifo: fix inaccurate comment 2018-03-27 11:15:42 +02:00
klist.c
kobject.c kobject: don't use WARN for registration failures 2018-04-23 13:14:55 +02:00
kobject_uevent.c net: Drop pernet_operations::async 2018-03-27 13:18:09 -04:00
kstrtox.c
kstrtox.h
lcm.c
libcrc32c.c libcrc32c: Add crc32c_impl function 2018-03-26 15:09:38 +02:00
list_debug.c lib/list_debug.c: print unmangled addresses 2018-04-11 10:28:35 -07:00
list_sort.c
llist.c
locking-selftest-hardirq.h
locking-selftest-mutex.h
locking-selftest-rlock-hardirq.h
locking-selftest-rlock-softirq.h
locking-selftest-rlock.h
locking-selftest-rsem.h
locking-selftest-rtmutex.h
locking-selftest-softirq.h
locking-selftest-spin-hardirq.h
locking-selftest-spin-softirq.h
locking-selftest-spin.h
locking-selftest-wlock-hardirq.h
locking-selftest-wlock-softirq.h
locking-selftest-wlock.h
locking-selftest-wsem.h
locking-selftest.c
lockref.c lockref: Add lockref_put_not_zero 2018-04-12 09:41:19 -07:00
logic_pio.c lib: Add generic PIO mapping method 2018-03-21 17:18:34 -05:00
lru_cache.c
lshrdi3.c
memory-notifier-error-inject.c
memweight.c
muldi3.c
net_utils.c
netdev-notifier-error-inject.c
nlattr.c
nmi_backtrace.c
nodemask.c
notifier-error-inject.c
notifier-error-inject.h
of-reconfig-notifier-error-inject.c
oid_registry.c
once.c
parman.c
parser.c
pci_iomap.c
percpu-refcount.c percpu_ref: Update doc to dissuade users from depending on internal RCU grace periods 2018-03-19 10:09:44 -07:00
percpu_counter.c
percpu_ida.c
percpu_test.c
plist.c
pm-notifier-error-inject.c
prime_numbers.c
radix-tree.c radix tree: use GFP_ZONEMASK bits of gfp_t for flags 2018-04-11 10:28:39 -07:00
random32.c
ratelimit.c
rational.c
rbtree.c
rbtree_test.c
reciprocal_div.c
refcount.c
rhashtable.c rhashtable: add schedule points 2018-03-31 23:25:39 -04:00
sbitmap.c blk-mq: avoid starving tag allocation after allocating process migrates 2018-05-24 11:00:39 -06:00
scatterlist.c lib/scatterlist: add sg_init_marker() helper 2018-03-30 22:50:15 +02:00
seq_buf.c
sg_pool.c
sg_split.c
sha1.c
sha256.c kernel/kexec_file.c: move purgatories sha256 to common code 2018-04-13 17:10:28 -07:00
show_mem.c
siphash.c
smp_processor_id.c
sort.c
stackdepot.c lib/stackdepot.c: use a non-instrumented version of memcmp() 2018-02-06 18:32:44 -08:00
stmp_device.c
string.c
string_helpers.c
strncpy_from_user.c
strnlen_user.c
swiotlb.c swiotlb: fix inversed DMA_ATTR_NO_WARN test 2018-05-02 14:48:55 +02:00
syscall.c
test-kstrtox.c
test-string_helpers.c
test_bitmap.c lib/test_bitmap.c: do not accidentally use stack VLA 2018-04-11 10:28:35 -07:00
test_bpf.c test_bpf: Fix NULL vs IS_ERR() check in test_skb_segment() 2018-03-29 14:33:29 -04:00
test_debug_virtual.c
test_firmware.c headers: untangle kmemleak.h from mm.h 2018-04-05 21:36:27 -07:00
test_hash.c
test_hexdump.c
test_kasan.c kasan: fix invalid-free test crashing the kernel 2018-04-11 10:28:32 -07:00
test_kmod.c lib/test_kmod.c: fix limit check on number of test devices created 2018-03-09 16:40:02 -08:00
test_list_sort.c
test_module.c
test_parman.c
test_printf.c
test_rhashtable.c test_rhashtable: add test case for rhltable with duplicate objects 2018-03-07 10:44:03 -05:00
test_siphash.c
test_sort.c lib/test_sort.c: add module unload support 2018-02-06 18:32:45 -08:00
test_static_key_base.c
test_static_keys.c
test_string.c
test_sysctl.c
test_ubsan.c lib/test_ubsan.c: make test_ubsan_misaligned_access() static 2018-04-11 10:28:35 -07:00
test_user_copy.c treewide: simplify Kconfig dependencies for removed archs 2018-03-26 15:55:57 +02:00
test_uuid.c
textsearch.c textsearch: fix kernel-doc warnings and add kernel-api section 2018-04-16 18:53:13 -04:00
timerqueue.c
ts_bm.c
ts_fsm.c
ts_kmp.c
ubsan.c lib/ubsan: remove returns-nonnull-attribute checks 2018-02-06 18:32:46 -08:00
ubsan.h lib/ubsan: remove returns-nonnull-attribute checks 2018-02-06 18:32:46 -08:00
ucmpdi2.c
ucs2_string.c
usercopy.c
uuid.c
vsprintf.c proc: add seq_put_decimal_ull_width to speed up /proc/pid/smaps 2018-04-11 10:28:33 -07:00
win_minmax.c
xxhash.c