path: root/lib/kobject.c
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authorWill Deacon <will.deacon@arm.com>2013-09-26 17:27:00 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2013-09-27 09:15:01 -0700
commitd2212b4dce596fee83e5c523400bf084f4cc816c (patch)
tree811e0dd289daad8bdebdeef37100587f647f75c1 /lib/kobject.c
parent4b97280675f45c1650ee4e388bd711ecbb18c4b4 (diff)
lockref: allow relaxed cmpxchg64 variant for lockless updates
The 64-bit cmpxchg operation on the lockref is ordered by virtue of hazarding between the cmpxchg operation and the reference count manipulation. On weakly ordered memory architectures (such as ARM), it can be of great benefit to omit the barrier instructions where they are not needed. This patch moves the lockless lockref code over to a cmpxchg64_relaxed operation, which doesn't provide barrier semantics. If the operation isn't defined, we simply #define it as the usual 64-bit cmpxchg macro. Cc: Waiman Long <Waiman.Long@hp.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/kobject.c')
0 files changed, 0 insertions, 0 deletions