Re: [PATCH 03/11] locking, rwsem: introduce basis for down_write_killable

[Peter Zijlstra]

On Mon, Apr 04, 2016 at 11:17:00AM +0200, Michal Hocko wrote:
> > >@@ -486,21 +487,39 @@ struct rw_semaphore __sched *rwsem_down_write_failed(struct rw_semaphore *sem)
> > >
> > >		/* Block until there are no active lockers. */
> > >		do {
> > >+			if (signal_pending_state(state, current)) {
> > 
> >                           ^^ unlikely()?
> 
> The generated code is identical after I've added unlikely. I haven't
> tried more gcc versions (mine is 5.3.1) but is this worth it?

Both signal_pending() and __fatal_signal_pending() already have an
unlikely(), which is why adding it here is superfluous.