On Mon, Mar 27, 2017 at 03:33:43PM +0100, Juri Lelli wrote:
> > diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
> > index a2ce590..49c93b9 100644
> > --- a/kernel/sched/deadline.c
> > +++ b/kernel/sched/deadline.c
> > @@ -1324,7 +1324,7 @@ static int find_later_rq(struct task_struct *task)
> > struct sched_domain *sd;
> > struct cpumask *later_mask =
> > this_cpu_cpumask_var_ptr(local_cpu_mask_dl);
> > int this_cpu = smp_processor_id();
> > - int best_cpu, cpu = task_cpu(task);
> > + int cpu = task_cpu(task);
> >
> > /* Make sure the mask is initialized first */
> > if (unlikely(!later_mask))
> > @@ -1337,17 +1337,14 @@ static int find_later_rq(struct task_struct *task)
> > * We have to consider system topology and task affinity
> > * first, then we can look for a suitable cpu.
> > */
> > - best_cpu = cpudl_find(&task_rq(task)->rd->cpudl,
> > - task, later_mask);
> > - if (best_cpu == -1)
> > + if (cpudl_find(&task_rq(task)->rd->cpudl, task, later_mask) == -1)
>
> It seems that with this we loose the last user of the current return
> value of cpudl_find() (heap maximum). I guess we want to change the
> return value to be (int)bool, as in rt, so that we can simplify this and
> the conditions in check_preempt_equal_dl.
Hi Juri,
Actually I changed the return value to be bool, but didn't include the
patch since it looks not that valuable. But I will add it if you also
think so. ;)
>
> > return -1;
> >
> > /*
> > - * If we are here, some target has been found,
> > - * the most suitable of which is cached in best_cpu.
> > - * This is, among the runqueues where the current tasks
> > - * have later deadlines than the task's one, the rq
> > - * with the latest possible one.
> > + * If we are here, some targets have been found, including
> > + * the most suitable which is, among the runqueues where the
> > + * current tasks have later deadlines than the task's one, the
> > + * rq with the latest possible one.
> > *
> > * Now we check how well this matches with task's
> > * affinity and system topology.
> > @@ -1367,6 +1364,7 @@ static int find_later_rq(struct task_struct *task)
> > rcu_read_lock();
> > for_each_domain(cpu, sd) {
> > if (sd->flags & SD_WAKE_AFFINE) {
> > + int closest_cpu;
>
> Can we still call this best_cpu, so that we are aligned with rt?
OK. I will rename it to best_cpu.
Thanks,
Byungchul
