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| author | Oleg Nesterov <oleg@tv-sign.ru> | 2008-02-24 00:03:29 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2008-02-24 04:52:36 +0300 |
| commit | 02c608c1fefe821a4c6fc34c45a0dea3cebf4764 (patch) | |
| tree | 8fd360da8bc83dd45ecec5621791baa73ddfac70 /include/asm-sparc/spinlock.h | |
| parent | 2dda81ca31dc73e695ff8b83351f7aaefbef192a (diff) | |
| download | linux-02c608c1fefe821a4c6fc34c45a0dea3cebf4764.tar.xz | |
documentation: atomic_add_unless() doesn't imply mb() on failure
(sorry for being offtpoic, but while experts are here...)
A "typical" implementation of atomic_add_unless() can return 0 immediately
after the first atomic_read() (before doing cmpxchg). In that case it doesn't
provide any barrier semantics. See include/asm-ia64/atomic.h as an example.
We should either change the implementation, or fix the docs.
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/asm-sparc/spinlock.h')
0 files changed, 0 insertions, 0 deletions