From: Valentin Schneider <valentin.schneider@arm.com>
To: Vincent Guittot <vincent.guittot@linaro.org>,
mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com,
dietmar.eggemann@arm.com, rostedt@goodmis.org,
bsegall@google.com, mgorman@suse.de, bristot@redhat.com,
linux-kernel@vger.kernel.org, joel@joelfernandes.org
Cc: fweisbec@gmail.com, tglx@linutronix.de, qais.yousef@arm.com,
Vincent Guittot <vincent.guittot@linaro.org>
Subject: Re: [PATCH 7/7 v3] sched/fair: reduce the window for duplicated update
Date: Fri, 12 Feb 2021 19:19:58 +0000 [thread overview]
Message-ID: <jhj4kiht7oh.mognet@arm.com> (raw)
In-Reply-To: <20210212141744.24284-8-vincent.guittot@linaro.org>
On 12/02/21 15:17, Vincent Guittot wrote:
> Start to update last_blocked_load_update_tick to reduce the possibility
> of another cpu starting the update one more time
>
IIUC this can happen if e.g. a CPU is busy updating load in
update_blocked_averages() while another enters update_nohz_stats() for the
same rq. They'll be serialized by the RQ lock, but both can still enter
update_blocked_averages() at roughly the same time.
Shouldn't then the rq->last_blocked_load_update_tick check be either
deferred to or re-done within update_blocked_averages(), with the rq lock
held?
prev parent reply other threads:[~2021-02-12 19:21 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-12 14:17 [PATCH 0/7 v3] move update blocked load outside newidle_balance Vincent Guittot
2021-02-12 14:17 ` [PATCH 1/7 v3] sched/fair: remove update of blocked load from newidle_balance Vincent Guittot
2021-02-12 14:17 ` [PATCH 2/7 v3] sched/fair: remove unused return of _nohz_idle_balance Vincent Guittot
2021-02-12 14:17 ` [PATCH 3/7 v3] sched/fair: remove unused parameter of update_nohz_stats Vincent Guittot
2021-02-12 14:17 ` [PATCH 4/7 v3] sched/fair: merge for each idle cpu loop of ILB Vincent Guittot
2021-02-12 14:17 ` [PATCH 5/7 v3] sched/fair: reorder newidle_balance pulled_task tests Vincent Guittot
2021-02-12 14:17 ` [PATCH 6/7 v3] sched/fair: trigger the update of blocked load on newly idle cpu Vincent Guittot
2021-02-12 19:19 ` Valentin Schneider
2021-02-15 15:02 ` Vincent Guittot
2021-02-17 11:51 ` Valentin Schneider
2021-02-17 15:34 ` Vincent Guittot
2021-02-12 14:17 ` [PATCH 7/7 v3] sched/fair: reduce the window for duplicated update Vincent Guittot
2021-02-12 19:19 ` Valentin Schneider [this message]
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