From 9659e1eeee28f7025b6545934d644d19e9c6e603 Mon Sep 17 00:00:00 2001 From: Xunlei Pang Date: Mon, 19 Jan 2015 04:49:37 +0000 Subject: sched/deadline: Remove cpu_active_mask from cpudl_find() cpu_active_mask is rarely changed (only on hotplug), 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 when a task is put onto a dying cpu (which rq_offline_dl() can't handle in a timely fashion), it will be handled through _cpu_down()->...->multi_cpu_stop()->migration_call() ->migrate_tasks(), preventing the task from hanging on the dead cpu. Cc: Juri Lelli Signed-off-by: Xunlei Pang [peterz: changelog] Signed-off-by: Peter Zijlstra (Intel) Link: http://lkml.kernel.org/r/1421642980-10045-2-git-send-email-pang.xunlei@linaro.org Cc: Linus Torvalds Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar 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) && -- cgit v0.10.2