On Fri, Nov 20, 2020 at 10:56:09AM +1100, Singh, Balbir wrote:
[..]
> > +#ifdef CONFIG_SMP
> > +static struct task_struct *pick_task_fair(struct rq *rq)
> > +{
> > + struct cfs_rq *cfs_rq = &rq->cfs;
> > + struct sched_entity *se;
> > +
> > + if (!cfs_rq->nr_running)
> > + return NULL;
> > +
> > + do {
> > + struct sched_entity *curr = cfs_rq->curr;
> > +
> > + se = pick_next_entity(cfs_rq, NULL);
> > +
> > + if (curr) {
> > + if (se && curr->on_rq)
> > + update_curr(cfs_rq);
> > +
> > + if (!se || entity_before(curr, se))
> > + se = curr;
> > + }
>
> Do we want to optimize this a bit
>
> if (curr) {
> if (!se || entity_before(curr, se))
> se = curr;
>
> if ((se != curr) && curr->on_rq)
> update_curr(cfs_rq);
>
> }
Do you see a difference in codegen? What's the optimization?
Also in later patches this code changes, so it should not matter:
See: 3e0838fa3c51 ("sched/fair: Fix pick_task_fair crashes due to empty rbtree")
thanks,
- Joel
