rwsem: skip initial trylock in rwsem_down_write_failed

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We can skip the initial trylock in rwsem_down_write_failed() if there
are known active lockers already, thus saving one likely-to-fail
cmpxchg.

Signed-off-by: Michel Lespinasse <walken@google.com>
Reviewed-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

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Michel Lespinasse 2013-05-07 06:45:57 -07:00 • committed by Linus Torvalds

parent a7d2c573ae

commit 9b0fc9c09f

1 changed files with 9 additions and 8 deletions

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lib/rwsem.c

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