On Fri, May 12, 2017 at 10:05:43AM +0900, Byungchul Park wrote: > pick_next_pushable_task(rq) has BUG_ON(rq_cpu != task_cpu(task)) when > it returns a task other than NULL, which means that task_cpu(task) must > be rq->cpu. So if task == next_task, then task_cpu(next_task) must be > rq->cpu as well. Remove the redundant condition and make code simpler. > > By this patch, unnecessary one branch and two LOAD operations in 'if' > statement can be avoided.
+cc [email protected] +cc [email protected] +cc [email protected] > > Signed-off-by: Byungchul Park <[email protected]> > Reviewed-by: Steven Rostedt (VMware) <[email protected]> > Reviewed-by: Juri Lelli <[email protected]> > Reviewed-by: Daniel Bristot de Oliveira <[email protected]> > --- > kernel/sched/rt.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c > index 4101f9d..5abd9a52 100644 > --- a/kernel/sched/rt.c > +++ b/kernel/sched/rt.c > @@ -1820,7 +1820,7 @@ static int push_rt_task(struct rq *rq) > * pushing. > */ > task = pick_next_pushable_task(rq); > - if (task_cpu(next_task) == rq->cpu && task == next_task) { > + if (task == next_task) { > /* > * The task hasn't migrated, and is still the next > * eligible task, but we failed to find a run-queue > -- > 1.9.1
