Messages in this thread | | | Date | Mon, 19 Jun 2023 20:18:06 +0800 | Subject | Re: [External] [tip: sched/core] sched/core: Avoid double calling update_rq_clock() in __balance_push_cpu_stop() | From | Hao Jia <> |
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On 2023/6/19 tip-bot2 for Hao Jia wrote: > The following commit has been merged into the sched/core branch of tip: > > Commit-ID: 96500560f0c73c71bca1b27536c6254fa0e8ce37 > Gitweb: https://git.kernel.org/tip/96500560f0c73c71bca1b27536c6254fa0e8ce37 > Author: Hao Jia <jiahao.os@bytedance.com> > AuthorDate: Tue, 13 Jun 2023 16:20:10 +08:00 > Committer: Peter Zijlstra <peterz@infradead.org> > CommitterDate: Fri, 16 Jun 2023 22:08:12 +02:00 > > sched/core: Avoid double calling update_rq_clock() in __balance_push_cpu_stop() > > There is a double update_rq_clock() invocation: > > __balance_push_cpu_stop() > update_rq_clock() > __migrate_task() > update_rq_clock() > > Sadly select_fallback_rq() also needs update_rq_clock() for > __do_set_cpus_allowed(), it is not possible to remove the update from > __balance_push_cpu_stop(). So remove it from __migrate_task() and > ensure all callers of this function call update_rq_clock() prior to > calling it. > Hi Peter,
Thank you very much for refactoring these commit messages to make it clearer and more concise.
Thanks, Hao
> Signed-off-by: Hao Jia <jiahao.os@bytedance.com> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> > Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> > Link: https://lkml.kernel.org/r/20230613082012.49615-3-jiahao.os@bytedance.com > --- > kernel/sched/core.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index 442efe5..c7db597 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -2546,7 +2546,6 @@ static struct rq *__migrate_task(struct rq *rq, struct rq_flags *rf, > if (!is_cpu_allowed(p, dest_cpu)) > return rq; > > - update_rq_clock(rq); > rq = move_queued_task(rq, rf, p, dest_cpu); > > return rq; > @@ -2604,10 +2603,12 @@ static int migration_cpu_stop(void *data) > goto out; > } > > - if (task_on_rq_queued(p)) > + if (task_on_rq_queued(p)) { > + update_rq_clock(rq); > rq = __migrate_task(rq, &rf, p, arg->dest_cpu); > - else > + } else { > p->wake_cpu = arg->dest_cpu; > + } > > /* > * XXX __migrate_task() can fail, at which point we might end
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