From: Peter Zijlstra <peterz@infradead.org>
To: wuchi <wuchi.zero@gmail.com>
Cc: mingo@redhat.com, juri.lelli@redhat.com,
vincent.guittot@linaro.org, dietmar.eggemann@arm.com,
rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de,
bristot@redhat.com, vschneid@redhat.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] sched/core: Reduce cost of sched_move_task when config autogroup
Date: Mon, 20 Mar 2023 09:28:11 +0100 [thread overview]
Message-ID: <20230320082811.GD2194297@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20230319075643.28312-1-wuchi.zero@gmail.com>
On Sun, Mar 19, 2023 at 03:56:43PM +0800, wuchi wrote:
> Some sched_move_task calls of autogroup is useless when the
> task_struct->sched_task_group isn't changed because of task_group
> of cpu_cgroup overlay task_group of autogroup. The overlay key codes
> are as follows:
>
> sched_cgroup_fork->autogroup_task_group->task_wants_autogroup
> sched_change_group->autogroup_task_group->autogroup_task_group
>
> sched_move_task eg:
> task A belongs to cpu_cgroup0 and autogroup0, it will always to
> cpu_cgroup0 when doing exit. So there is no need to do {de|en}queue.
> The call graph is as follow.
>
> do_exit
> sched_autogroup_exit_task
> sched_move_task
> dequeue_task
> sched_change_group
> A.sched_task_group = sched_get_task_group
> enqueue_task
>
> So do some check before dequeue task in sched_move_task.
No immediate objection; but the $subject seems to suggest you did this
for performance reasons, yet there are no performance results in this
Changelog. How much does this save under what load?
next prev parent reply other threads:[~2023-03-20 8:28 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-19 7:56 [PATCH] sched/core: Reduce cost of sched_move_task when config autogroup wuchi
2023-03-20 8:28 ` Peter Zijlstra [this message]
2023-03-20 12:40 ` chi wu
2023-03-20 15:13 ` Peter Zijlstra
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