From: Peter Zijlstra <peterz@infradead.org>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: mingo@redhat.com, juri.lelli@redhat.com,
dietmar.eggemann@arm.com, rostedt@goodmis.org,
bsegall@google.com, mgorman@suse.de, vschneid@redhat.com,
linux-kernel@vger.kernel.org, kprateek.nayak@amd.com,
pauld@redhat.com, efault@gmx.de, luis.machado@arm.com
Subject: Re: [PATCH 2/9] sched/fair: Add new cfs_rq.h_nr_enqueued
Date: Thu, 28 Nov 2024 10:56:43 +0100 [thread overview]
Message-ID: <20241128095643.GB24400@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <20241128092750.2541735-3-vincent.guittot@linaro.org>
On Thu, Nov 28, 2024 at 10:27:43AM +0100, Vincent Guittot wrote:
> With delayed dequeued feature, a sleeping sched_entity remains enqueued
> in the rq until its lag has elapsed. As a result, it stays also visible
> in the statistics that are used to balance the system and in particular
> the field h_nr_running when the sched_entity is associated to a task.
>
> Create a new h_nr_enqueued that tracks all enqueued tasks and restore the
> behavior of h_nr_running i.e. tracking the number of fair tasks that want
> to run.
Isn't h_nr_enqueued := h_nr_running - h_nr_delayed ? Does it really make
sense to have another variable that is so trivially computable?
Also naming; h_nr_enqueued isn't really adequate I feel, because the
whole problem is that the delayed tasks are still very much enqueued.
next prev parent reply other threads:[~2024-11-28 9:56 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-28 9:27 [PATCH 0/9] sched/fair: Fix statistics with delayed dequeue Vincent Guittot
2024-11-28 9:27 ` [PATCH 1/9] sched/eevdf: More PELT vs DELAYED_DEQUEUE Vincent Guittot
2024-11-28 9:27 ` [PATCH 2/9] sched/fair: Add new cfs_rq.h_nr_enqueued Vincent Guittot
2024-11-28 9:56 ` Peter Zijlstra [this message]
2024-11-28 10:24 ` Vincent Guittot
2024-11-28 10:27 ` Peter Zijlstra
2024-11-28 9:27 ` [PATCH 3/9] sched/fair: Rename cfs_rq.idle_h_nr_running into h_nr_idle Vincent Guittot
2024-11-28 9:27 ` [PATCH 4/9] sched/fair: Remove unused cfs_rq.idle_nr_running Vincent Guittot
2024-11-28 9:27 ` [PATCH 5/9] sched/fair: Rename cfs_rq.nr_running into nr_enqueued Vincent Guittot
2024-11-28 9:27 ` [PATCH 6/9] sched/fair: Removed unsued cfs_rq.h_nr_delayed Vincent Guittot
2024-11-28 10:03 ` Peter Zijlstra
2024-11-28 10:15 ` Peter Zijlstra
2024-11-28 10:32 ` Vincent Guittot
2024-11-28 9:27 ` [PATCH 7/9] sched/fair: Do not try to migrate delayed dequeue task Vincent Guittot
2024-11-28 9:49 ` Peter Zijlstra
2024-11-28 10:03 ` Vincent Guittot
2024-11-28 10:15 ` Peter Zijlstra
2024-11-28 9:27 ` [PATCH 8/9] sched/fair: Fix sched_can_stop_tick() for fair tasks Vincent Guittot
2024-11-28 9:27 ` [PATCH 9/9] sched/fair: Fix variable declaration position Vincent Guittot
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