On Tue, 19 May 2015, Davidlohr Bueso wrote: > Avoid unnecessary cmpxchg calls, all of our other locks > use it as well. > > Signed-off-by: Davidlohr Bueso <dbu...@suse.de> > --- > kernel/locking/rtmutex.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c > index 74188d8..1d5cc9d 100644 > --- a/kernel/locking/rtmutex.c > +++ b/kernel/locking/rtmutex.c > @@ -74,7 +74,9 @@ static void fixup_rt_mutex_waiters(struct rt_mutex *lock) > * set up. > */ > #ifndef CONFIG_DEBUG_RT_MUTEXES > -# define rt_mutex_cmpxchg(l,c,n) (cmpxchg(&l->owner, c, n) == c) > +# define rt_mutex_cmpxchg(l,c,n) \ > + (l->owner == c && cmpxchg(&l->owner, c, n) == c)
Errm. How does that improve stuff like rt_mutex_lock() ? Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/