author | Manfred Spraul <manfred@colorfullife.com> | |
Wed, 26 May 2010 21:43:42 +0000 (14:43 -0700) | ||
committer | Linus Torvalds <torvalds@linux-foundation.org> | |
Thu, 27 May 2010 16:12:49 +0000 (09:12 -0700) | ||
commit | 31a7c4746e9925512afab30557dd445d677cc802 | |
tree | 7f7b39331aa51b77c159b046d406b12aec24de11 | tree | snapshot (tar.xz tar.gz zip) |
parent | 0a2b9d4c79671b05956806ede5d054e03ae56280 | commit | diff |
ipc/sem.c: cacheline align the ipc spinlock for semaphores
Cacheline align the spinlock for sysv semaphores. Without the patch, the
spinlock and sem_otime [written by every semop that modified the array]
and sem_base [read in the hot path of try_atomic_semop()] can be in the
same cacheline.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cacheline align the spinlock for sysv semaphores. Without the patch, the
spinlock and sem_otime [written by every semop that modified the array]
and sem_base [read in the hot path of try_atomic_semop()] can be in the
same cacheline.
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Zach Brown <zach.brown@oracle.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/sem.h | diff | blob | history |