Michel Lespinasse 25c3932596 rwsem: do not block readers at head of queue if other readers are active ...

This change fixes a race condition where a reader might determine it
needs to block, but by the time it acquires the wait_lock the rwsem has
active readers and no queued waiters.

In this situation the reader can run in parallel with the existing
active readers; it does not need to block until the active readers
complete.

Thanks to Peter Hurley for noticing this possible race.

Signed-off-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2013-05-07 07:20:17 -07:00

..

lzo

lib/lzo: Update LZO compression to current upstream version

2013-02-20 19:36:01 +01:00

mpi

mpilib: use DIV_ROUND_UP and remove unused macros

2013-02-01 16:28:32 +11:00

raid6

lib/raid6: build proper files on corresponding arch

2012-12-13 19:51:04 +11:00

reed_solomon

…

xz

decompressors: fix typo "POWERPC"

2013-03-13 15:21:48 -07:00

zlib_deflate

zlib: slim down zlib_deflate() workspace when possible

2011-03-22 17:44:17 -07:00

zlib_inflate

…

.gitignore

X.509: Implement simple static OID registry

2012-10-08 13:50:18 +10:30

argv_split.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

asn1_decoder.c

Nothing all that exciting; a new module-from-fd syscall for those who want

2012-12-19 07:55:08 -08:00

atomic64_test.c

atomic64_test: simplify the #ifdef for atomic64_dec_if_positive() test

2012-07-30 17:25:16 -07:00

atomic64.c

lib: atomic64: Initialize locks statically to fix early users

2012-12-20 13:50:16 -08:00

audit.c

audit: support the "standard" <asm-generic/unistd.h>

2011-05-04 14:41:28 -04:00

average.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

bcd.c

usb/core: use bin2bcd() for bcdDevice in RH

2012-09-10 11:13:16 -07:00

bch.c

lib: add shared BCH ECC library

2011-03-11 14:25:50 +00:00

bitmap.c

propagate name change to comments in kernel source

2012-12-06 10:39:54 +01:00

bitrev.c

…

bsearch.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

btree.c

btree: catch NULL value before it does harm

2012-06-07 14:43:55 -07:00

bug.c

taint: add explicit flag to show whether lock dep is still OK.

2013-01-21 17:17:57 +10:30

build_OID_registry

X.509: Implement simple static OID registry

2012-10-08 13:50:18 +10:30

bust_spinlocks.c

printk: Provide a wake_up_klogd() off-case

2013-03-22 16:41:20 -07:00

check_signature.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

checksum.c

asm-generic headers: Allow yet more arch overrides in checksum.h

2013-02-11 20:00:33 +05:30

clz_tab.c

lib: Fix multiple definitions of clz_tab

2012-02-02 10:34:23 +11:00

cmdline.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

cordic.c

Docs: wording: functions -> algorithm

2011-10-29 21:20:22 +02:00

cpu_rmap.c

lib: cpu_rmap: avoid flushing all workqueues

2013-01-11 14:54:54 -08:00

cpu-notifier-error-inject.c

cpu: rewrite cpu-notifier-error-inject module

2012-07-30 17:25:22 -07:00

cpumask.c

bootmem: fix wrong call parameter for free_bootmem()

2012-12-11 17:22:28 -08:00

crc7.c

…

crc8.c

lib: crc8: add new library module providing crc8 algorithm

2011-06-03 15:01:06 -04:00

crc16.c

…

crc32.c

sections: fix const sections for crc32 table

2012-10-06 03:04:46 +09:00

crc32defs.h

crc32: select an algorithm via Kconfig

2012-03-23 16:58:38 -07:00

crc-ccitt.c

…

crc-itu-t.c

…

crc-t10dif.c

…

ctype.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

debug_locks.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

debugobjects.c

hlist: drop the node parameter from iterators

2013-02-27 19:10:24 -08:00

dec_and_lock.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

decompress_bunzip2.c

decompress_bunzip2: remove invalid vi modeline

2011-12-06 10:00:05 +01:00

decompress_inflate.c

decompressors: check input size in decompress_inflate.c

2011-01-13 08:03:25 -08:00

decompress_unlzma.c

treewide: Fix comment and string typo 'bufer'

2011-12-06 09:53:40 +01:00

decompress_unlzo.c

lib/lzo: Rename lzo1x_decompress.c to lzo1x_decompress_safe.c

2013-02-20 19:36:00 +01:00

decompress_unxz.c

Fix common misspellings

2011-03-31 11:26:23 -03:00

decompress.c

lib/decompress.c add __init to decompress_method and data

2012-10-06 03:05:32 +09:00

devres.c

lib/devres.c: fix misplaced #endif

2013-02-27 19:10:09 -08:00

digsig.c

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

2013-02-21 08:18:12 -08:00

div64.c

lib: correct link to the original source for div64_u64

2012-06-28 11:51:39 +02:00

dma-debug.c

dma-debug: update DMA debug API to better handle multiple mappings of a buffer

2013-03-22 16:41:20 -07:00

dump_stack.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

dynamic_debug.c

dynamic_debug: add pr_errs before -EINVALs

2013-01-17 12:19:09 -08:00

dynamic_queue_limits.c

bql: Avoid possible inconsistent calculation.

2012-05-31 18:18:17 -04:00

earlycpio.c

lib: Add early cpio decoder

2012-09-30 18:02:20 -07:00

extable.c

…

fault-inject.c

fault-inject: avoid call to random32() if fault injection is disabled

2012-06-20 14:39:36 -07:00

fdt_ro.c

of/lib: Allow scripts/dtc/libfdt to be used from kernel code

2012-07-23 13:54:52 +01:00

fdt_rw.c

of/lib: Allow scripts/dtc/libfdt to be used from kernel code

2012-07-23 13:54:52 +01:00

fdt_strerror.c

of/lib: Allow scripts/dtc/libfdt to be used from kernel code

2012-07-23 13:54:52 +01:00

fdt_sw.c

of/lib: Allow scripts/dtc/libfdt to be used from kernel code

2012-07-23 13:54:52 +01:00

fdt_wip.c

of/lib: Allow scripts/dtc/libfdt to be used from kernel code

2012-07-23 13:54:52 +01:00

fdt.c

of/lib: Allow scripts/dtc/libfdt to be used from kernel code

2012-07-23 13:54:52 +01:00

find_last_bit.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

find_next_bit.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

flex_array.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

flex_proportions.c

lib/flex_proportions.c: fix corruption of denominator in flexible proportions

2012-09-25 08:59:21 -07:00

gcd.c

lib/gcd.c: prevent possible div by 0

2012-10-06 03:04:57 +09:00

gen_crc32table.c

sections: fix const sections for crc32 table

2012-10-06 03:04:46 +09:00

genalloc.c

genalloc: stop crashing the system when destroying a pool

2012-10-25 14:37:52 -07:00

halfmd4.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

hexdump.c

dynamic_debug: dynamic hex dump

2013-01-17 12:19:09 -08:00

hweight.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

idr.c

idr: idr_alloc() shouldn't trigger lowmem warning when preloaded

2013-03-13 15:21:49 -07:00

inflate.c

…

int_sqrt.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

interval_tree_test_main.c

random32: rename random32 to prandom

2012-12-17 17:15:26 -08:00

interval_tree.c

mm: interval tree updates

2012-10-09 16:22:40 +09:00

iomap_copy.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

iomap.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

iommu-helper.c

The following text was taken from the original review request:

2012-03-24 10:24:31 -07:00

ioremap.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

irq_regs.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

is_single_threaded.c

…

jedec_ddr_data.c

ddr: add LPDDR2 data from JESD209-2

2012-05-02 00:04:06 -07:00

kasprintf.c

lib/kasprintf.c: use kmalloc_track_caller() to get accurate traces for kvasprintf

2012-10-11 08:50:15 +09:00

Kconfig

Move utf16 functions to kernel core and rename

2013-04-15 21:23:03 +01:00

Kconfig.debug

ImgTec Meta architecture changes for v3.9-rc1

2013-03-03 12:06:09 -08:00

Kconfig.kgdb

KGDB/KDB fixes and cleanups

2013-03-02 08:31:39 -08:00

Kconfig.kmemcheck

…

kfifo.c

kfifo: fix kfifo_alloc() and kfifo_init()

2013-02-27 19:10:23 -08:00

klist.c

Revert "driver core: check start node in klist_iter_init_node"

2012-04-19 19:17:30 -07:00

kobject_uevent.c

netlink: hide struct module parameter in netlink_kernel_create

2012-09-08 18:46:30 -04:00

kobject.c

kobject: fix kset_find_obj() race with concurrent last kobject_put()

2013-04-13 15:15:30 -07:00

kstrtox.c

kstrto*: add documentation

2012-12-17 17:15:22 -08:00

kstrtox.h

lib/kstrtox: common code between kstrto*() and simple_strto*() functions

2011-10-31 17:30:56 -07:00

lcm.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

libcrc32c.c

…

list_debug.c

rcu: Fix broken strings in RCU's source code.

2012-07-06 06:01:49 -07:00

list_sort.c

…

llist.c

Disintegrate and delete asm/system.h

2012-03-28 15:58:21 -07:00

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-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

lockdep: Selftest: convert spinlock to raw spinlock

2013-02-19 08:43:35 +01:00

lru_cache.c

hlist: drop the node parameter from iterators

2013-02-27 19:10:24 -08:00

Makefile

Move utf16 functions to kernel core and rename

2013-04-15 21:23:03 +01:00

md5.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

memory-notifier-error-inject.c

memory: memory notifier error injection module

2012-07-30 17:25:22 -07:00

memweight.c

string: introduce memweight()

2012-07-30 17:25:16 -07:00

nlattr.c

netlink: add minlen validation for the new signed types

2012-08-30 13:11:46 -04:00

notifier-error-inject.c

fault-injection: notifier error injection

2012-07-30 17:25:22 -07:00

notifier-error-inject.h

fault-injection: notifier error injection

2012-07-30 17:25:22 -07:00

of-reconfig-notifier-error-inject.c

powerpc+of: Rename and fix OF reconfig notifier error inject module

2012-12-14 10:32:52 +11:00

oid_registry.c

X.509: Add utility functions to render OIDs as strings

2012-10-08 13:50:18 +10:30

parser.c

lib/parser.c: fix up comments for valid return values from match_number

2013-02-21 17:22:25 -08:00

pci_iomap.c

lib: add NO_GENERIC_PCI_IOPORT_MAP

2012-01-31 23:19:47 +02:00

percpu_counter.c

switch the protection of percpu_counter list to spinlock

2012-07-31 09:28:31 +04:00

percpu-rwsem.c

percpu_rw_semaphore: add lockdep annotations

2012-12-17 17:15:18 -08:00

plist.c

lib/plist.c: make plist test announcements KERN_DEBUG

2012-10-06 03:04:58 +09:00

pm-notifier-error-inject.c

PM: PM notifier error injection module

2012-07-30 17:25:22 -07:00

prio_heap.c

…

proportions.c

locking, lib/proportions: Annotate prop_local_percpu::lock as raw

2011-09-13 11:11:50 +02:00

radix-tree.c

radix-tree: fix contiguous iterator

2012-06-05 10:46:40 -07:00

random32.c

prandom: introduce prandom_bytes() and prandom_bytes_state()

2012-12-17 17:15:26 -08:00

ratelimit.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

rational.c

lib: Change mail address of Oskar Schirmer

2012-05-17 15:18:37 +02:00

rbtree_test.c

random32: rename random32 to prandom

2012-12-17 17:15:26 -08:00

rbtree.c

lib/rbtree.c: avoid the use of non-static __always_inline

2013-01-11 14:54:56 -08:00

reciprocal_div.c

sch_red: Adaptative RED AQM

2011-12-08 19:52:43 -05:00

rwsem-spinlock.c

rwsem: simplify __rwsem_do_wake

2013-05-07 07:20:16 -07:00

rwsem.c

rwsem: do not block readers at head of queue if other readers are active

2013-05-07 07:20:17 -07:00

scatterlist.c

lib/scatterlist: use page iterator in the mapping iterator

2013-02-27 19:10:10 -08:00

sha1.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

show_mem.c

arch, mm: filter disallowed nodes from arch specific show_mem functions

2011-05-25 08:39:03 -07:00

smp_processor_id.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

sort.c

…

spinlock_debug.c

lib/spinlock_debug: avoid livelock in do_raw_spin_lock()

2012-10-06 03:04:57 +09:00

stmp_device.c

lib: add support for stmp-style devices

2012-04-20 23:27:08 +02:00

string_helpers.c

lib/string_helpers.c: make arrays static

2012-05-29 16:22:32 -07:00

string.c

The following text was taken from the original review request:

2012-03-24 10:24:31 -07:00

strncpy_from_user.c

word-at-a-time: make the interfaces truly generic

2012-05-26 11:33:40 -07:00

strnlen_user.c

lib: Fix generic strnlen_user for 32-bit big-endian machines

2012-05-27 20:59:46 -07:00

swiotlb.c

x86, kdump: Set crashkernel_low automatically

2013-04-17 12:35:32 -07:00

syscall.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

test-kstrtox.c

lib/test-kstrtox.c: mark const init data with __initconst instead of __initdata

2012-05-29 16:22:32 -07:00

textsearch.c

textsearch: doc - fix spelling in lib/textsearch.c.

2011-01-24 23:33:30 -08:00

timerqueue.c

The following text was taken from the original review request:

2012-03-24 10:24:31 -07:00

ts_bm.c

…

ts_fsm.c

…

ts_kmp.c

…

ucs2_string.c

Move utf16 functions to kernel core and rename

2013-04-15 21:23:03 +01:00

uuid.c

lib: reduce the use of module.h wherever possible

2012-03-07 15:04:04 -05:00

vsprintf.c

lib/vsprintf.c: add %pa format specifier for phys_addr_t types

2013-02-21 17:22:20 -08:00