| Message ID | 1421642980-10045-2-git-send-email-pang.xunlei@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
diff --git a/kernel/sched/cpudeadline.c b/kernel/sched/cpudeadline.c index fd9d3fb..c6acb07 100644 --- a/kernel/sched/cpudeadline.c +++ b/kernel/sched/cpudeadline.c @@ -108,8 +108,7 @@ int cpudl_find(struct cpudl *cp, struct task_struct *p, const struct sched_dl_entity *dl_se = &p->dl; if (later_mask && - cpumask_and(later_mask, cp->free_cpus, &p->cpus_allowed) && - cpumask_and(later_mask, later_mask, cpu_active_mask)) { + cpumask_and(later_mask, cp->free_cpus, &p->cpus_allowed)) { best_cpu = cpumask_any(later_mask); goto out; } else if (cpumask_test_cpu(cpudl_maximum(cp), &p->cpus_allowed) &&
cpu_active_mask is rarely changeable, so remove this operation to gain a little performance. If there is a change in cpu_active_mask, rq_online_dl() and rq_offline_dl() should take care of it normally, so cpudl:: free_cpus carries enough information for us. For the rare case(causing a task put onto a dying cpu) which rq_offline_dl() can't handle timely, then it can be handled through _cpu_down()->...->multi_cpu_stop()->migration_call() ->migrate_tasks(), preventing the task from hanging on the dead cpu. Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org> --- kernel/sched/cpudeadline.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)