Commit-ID: 308a623a40ce168eb234ea82c2bd13ff85a098d9 Gitweb: http://git.kernel.org/tip/308a623a40ce168eb234ea82c2bd13ff85a098d9 Author: Wanpeng Li <wanpeng...@linux.intel.com> AuthorDate: Fri, 31 Oct 2014 06:39:31 +0800 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Tue, 4 Nov 2014 07:17:52 +0100
sched/rt: Clean up check_preempt_equal_prio() This patch checks if current can be pushed/pulled somewhere else in advance to make logic clear, the same behavior as dl class. - If current can't be migrated, useless to reschedule, let's hope task can move out. - If task is migratable, so let's not schedule it and see if it can be pushed or pulled somewhere else. Signed-off-by: Wanpeng Li <wanpeng...@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> Cc: Juri Lelli <juri.le...@arm.com> Cc: Kirill Tkhai <ktk...@parallels.com> Cc: Steven Rostedt <rost...@goodmis.org> Cc: Linus Torvalds <torva...@linux-foundation.org> Link: http://lkml.kernel.org/r/1414708776-124078-1-git-send-email-wanpeng...@linux.intel.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- kernel/sched/rt.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index d024e6c..3d14312 100644 --- a/kernel/sched/rt.c +++ b/kernel/sched/rt.c @@ -1351,16 +1351,22 @@ out: static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) { - if (rq->curr->nr_cpus_allowed == 1) + /* + * Current can't be migrated, useless to reschedule, + * let's hope p can move out. + */ + if (rq->curr->nr_cpus_allowed == 1 || + !cpupri_find(&rq->rd->cpupri, rq->curr, NULL)) return; + /* + * p is migratable, so let's not schedule it and + * see if it is pushed or pulled somewhere else. + */ if (p->nr_cpus_allowed != 1 && cpupri_find(&rq->rd->cpupri, p, NULL)) return; - if (!cpupri_find(&rq->rd->cpupri, rq->curr, NULL)) - return; - /* * There appears to be other cpus that can accept * current and none to run 'p', so lets reschedule -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
