From: Manfred Spraul <manfred@colorfullife.com>
Date: Wed, 26 May 2010 21:43:42 +0000 (-0700)
Subject: ipc/sem.c: cacheline align the ipc spinlock for semaphores
X-Git-Tag: v2.6.35-rc1~134
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=31a7c4746e9925512afab30557dd445d677cc802;p=pandora-kernel.git

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>
---

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