From: Michel Lespinasse <walken@google.com>
Date: Tue, 7 May 2013 13:45:55 +0000 (-0700)
Subject: rwsem: use cmpxchg for trying to steal write lock
X-Git-Tag: omap-for-v3.10/dt-fixes-for-merge-window~14^2~7
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5ede972df1cd9294c82e9515949fd2103be81d7b;p=pandora-kernel.git

rwsem: use cmpxchg for trying to steal write lock

Using rwsem_atomic_update to try stealing the write lock forced us to
undo the adjustment in the failure path.  We can have simpler and faster
code by using cmpxchg instead.

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>
---

Reading git-diff-tree failed