From: Thomas Gleixner Date: Tue, 10 Jun 2014 20:53:40 +0000 (+0200) Subject: rtmutex: Simplify rtmutex_slowtrylock() X-Git-Tag: cleanup-for-v3.18~138^2~21 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=88f2b4c15e561bb5c28709d666364f273bf54b98;p=pandora-kernel.git rtmutex: Simplify rtmutex_slowtrylock() Oleg noticed that rtmutex_slowtrylock() has a pointless check for rt_mutex_owner(lock) != current. To avoid calling try_to_take_rtmutex() we really want to check whether the lock has an owner at all or whether the trylock failed because the owner is NULL, but the RT_MUTEX_HAS_WAITERS bit is set. This covers the lock is owned by caller situation as well. We can actually do this check lockless. trylock is taking a chance whether we take lock->wait_lock to do the check or not. Add comments to the function while at it. Reported-by: Oleg Nesterov Signed-off-by: Thomas Gleixner Reviewed-by: Steven Rostedt Reviewed-by: Lai Jiangshan --- Reading git-diff-tree failed