diff options
| author | Wanpeng Li <wanpeng.li@linux.intel.com> | 2014-10-31 06:39:31 +0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2014-11-04 07:17:52 +0100 |
| commit | 308a623a40ce168eb234ea82c2bd13ff85a098d9 (patch) | |
| tree | de29313f91c8c98c353e422cdaf423b6494dcbb8 /kernel/sched/rt.c | |
| parent | 75e23e49dbdd86aace375f599062aa67483a001b (diff) | |
| download | linux-308a623a40ce168eb234ea82c2bd13ff85a098d9.tar.gz | |
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.li@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Kirill Tkhai <ktkhai@parallels.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414708776-124078-1-git-send-email-wanpeng.li@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched/rt.c')
| -rw-r--r-- | kernel/sched/rt.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c index d024e6ce30ba..3d14312db7ea 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 |