Davidlohr Bueso 370b262c89 ipc/sem: avoid idr tree lookup for interrupted semop ... We can avoid the idr tree lookup (albeit possibly avoiding idr_find_fast()) when being awoken in EINTR, as the semid will not change in this context while blocked. Use the sma pointer directly and take the sem_lock, then re-check for RMID races. We continue to re-check the queue.status with the lock held such that we can detect situations where we where are dealing with a spurious wakeup but another task that holds the sem_lock updated the queue.status while we were spinning for it. Once we take the lock it obviously won't change again. Being the only caller, get rid of sem_obtain_lock() altogether. Link: http://lkml.kernel.org/r/1478708774-28826-3-git-send-email-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Manfred Spraul <manfred@colorfullife.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2016-12-14 16:04:08 -08:00
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compat.c
compat_mq.c
ipc_sysctl.c
Makefile
mq_sysctl.c
mqueue.c
msg.c
msgutil.c
namespace.c
sem.c	ipc/sem: avoid idr tree lookup for interrupted semop	2016-12-14 16:04:08 -08:00
shm.c
syscall.c
util.c
util.h