Jens Axboe c854ab5773 sbitmap: fix race in wait batch accounting ... If we have multiple callers of sbq_wake_up(), we can end up in a situation where the wait_cnt will continually go more and more negative. Consider the case where our wake batch is 1, hence wait_cnt will start out as 1. wait_cnt == 1 CPU0 CPU1 atomic_dec_return(), cnt == 0 atomic_dec_return(), cnt == -1 cmpxchg(-1, 0) (succeeds) [wait_cnt now 0] cmpxchg(0, 1) (fails) This ends up with wait_cnt being 0, we'll wakeup immediately next time. Going through the same loop as above again, and we'll have wait_cnt -1. For the case where we have a larger wake batch, the only difference is that the starting point will be higher. We'll still end up with continually smaller batch wakeups, which defeats the purpose of the rolling wakeups. Always reset the wait_cnt to the batch value. Then it doesn't matter who wins the race. But ensure that whomever does win the race is the one that increments the ws index and wakes up our batch count, loser gets to call __sbq_wake_up() again to account his wakeups towards the next active wait state index. Fixes: 6c0ca7ae29 ("sbitmap: fix wakeup hang after sbq resize") Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>		2018-05-14 12:17:31 -06:00
..
842
fonts
lz4
lzo
mpi	lib/mpi: Fix umul_ppmm() for MIPS64r6	2017-12-22 19:39:09 +11:00
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
argv_split.c
ashldi3.c	move libgcc.h to include/linux	2017-12-01 13:09:40 -08:00
ashrdi3.c	move libgcc.h to include/linux	2017-12-01 13:09:40 -08:00
asn1_decoder.c	ASN.1: check for error from ASN1_OP_END__ACT actions	2017-12-08 15:13:27 +00:00
assoc_array.c	lib/assoc_array: Remove smp_read_barrier_depends()	2017-12-04 10:52:56 -08:00
atomic64_test.c
atomic64.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	spinlock: Add library function to allocate spinlock buckets array	2017-12-11 09:58:39 -05:00
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	crypto: chacha20 - use rol32() macro from bitops.h	2018-01-12 23:03:01 +11:00
check_signature.c
checksum.c
clz_ctz.c
clz_tab.c
cmdline.c
cmpdi2.c	move libgcc.h to include/linux	2017-12-01 13:09:40 -08:00
compat_audit.c
cordic.c
cpu_rmap.c
cpumask.c	lib: optimize cpumask_next_and()	2018-02-06 18:32:44 -08:00
crc4.c
crc7.c
crc8.c
crc16.c
crc32.c
crc32defs.h
crc32test.c
crc-ccitt.c	lib/crc-ccitt: Add CCITT-FALSE CRC16 variant	2018-01-08 10:08:33 +00:00
crc-itu-t.c
crc-t10dif.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_bunzip2.c
decompress_inflate.c
decompress_unlz4.c
decompress_unlzma.c
decompress_unlzo.c
decompress_unxz.c
decompress.c
devres.c	devres: combine function devm_ioremap*	2018-03-15 18:08:55 +01:00
digsig.c
div64.c	A relatively calm cycle for the docs tree again.	2017-11-13 08:25:06 -08:00
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-debug-howto: fix optional/omitted ending line number to be LARGE instead of 0	2017-11-17 16:10:01 -08:00
dynamic_queue_limits.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2017-11-15 11:56:19 -08:00
earlycpio.c
error-inject.c	error-injection: Add injectable error types	2018-01-12 17:33:38 -08:00
errseq.c	errseq: Always report a writeback error once	2018-04-27 08:51:26 -04:00
extable.c
fault-inject.c
fdt_empty_tree.c
fdt_ro.c
fdt_rw.c
fdt_strerror.c
fdt_sw.c
fdt_wip.c
fdt.c
find_bit_benchmark.c	lib: optimize cpumask_next_and()	2018-02-06 18:32:44 -08:00
find_bit.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	lib/genalloc.c: make the avail variable an atomic_long_t	2017-11-17 16:10:02 -08:00
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_test.c	lib/rbtree-test: lower default params	2017-11-17 16:10:02 -08:00
interval_tree.c
iomap_copy.c
iomap.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
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
kfifo.c	kfifo: fix inaccurate comment	2018-03-27 11:15:42 +02:00
klist.c
kobject_uevent.c	net: Drop pernet_operations::async	2018-03-27 13:18:09 -04:00
kobject.c	kobject: don't use WARN for registration failures	2018-04-23 13:14:55 +02:00
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	move libgcc.h to include/linux	2017-12-01 13:09:40 -08:00
Makefile	lib: add testing module for UBSAN	2018-04-11 10:28:35 -07:00
memory-notifier-error-inject.c
memweight.c
muldi3.c	move libgcc.h to include/linux	2017-12-01 13:09:40 -08:00
net_utils.c
netdev-notifier-error-inject.c
nlattr.c	netlink: Relax attr validation for fixed length types	2017-12-07 14:00:57 -05:00
nmi_backtrace.c	lib/nmi_backtrace.c: fix kernel text address leak	2017-11-17 16:10:02 -08:00
nodemask.c
notifier-error-inject.c
notifier-error-inject.h
of-reconfig-notifier-error-inject.c
oid_registry.c	509: fix printing uninitialized stack memory when OID is empty	2017-12-08 15:13:28 +00:00
once.c
parman.c
parser.c
pci_iomap.c	PCI: Add SPDX GPL-2.0 when no license was specified	2018-01-26 11:45:16 -06:00
percpu_counter.c
percpu_ida.c
percpu_test.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
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	treewide: Switch DEFINE_TIMER callbacks to struct timer_list *	2017-11-21 15:57:05 -08:00
ratelimit.c
rational.c
rbtree_test.c	lib/rbtree-test: lower default params	2017-11-17 16:10:02 -08:00
rbtree.c	lib/rbtree,drm/mm: add rbtree_replace_node_cached()	2017-12-14 16:00:48 -08:00
reciprocal_div.c
refcount.c
rhashtable.c	rhashtable: add schedule points	2018-03-31 23:25:39 -04:00
sbitmap.c	sbitmap: fix race in wait batch accounting	2018-05-14 12:17:31 -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	lib: do not use print_symbol()	2018-01-05 15:24:00 +01:00
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_helpers.c
string.c	lib/strscpy: Shut up KASAN false-positives in strscpy()	2018-02-01 12:20:21 -08:00
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_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	lib/test: delete five error messages for failed memory allocations	2017-11-17 16:10:01 -08:00
test_module.c
test_parman.c
test_printf.c	printk: hash addresses printed with %p	2017-11-29 12:09:02 +11:00
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	lib: add module support to string tests	2017-11-17 16:10:01 -08:00
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
test-kstrtox.c
test-string_helpers.c
textsearch.c	textsearch: fix kernel-doc warnings and add kernel-api section	2018-04-16 18:53:13 -04:00
timerqueue.c	timerqueue: Document return values of timerqueue_add/del()	2017-12-29 23:13:10 +01:00
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	move libgcc.h to include/linux	2017-12-01 13:09:40 -08:00
ucs2_string.c
usercopy.c	Fix misannotated out-of-line _copy_to_user()	2017-12-11 09:35:11 -05:00
uuid.c	Documentation: add UUID/GUID to kernel-api	2017-12-11 15:03:08 -07:00
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