From: Valentin Schneider <valentin.schneider@arm.com>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: linux-kernel <linux-kernel@vger.kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Morten Rasmussen <morten.rasmussen@arm.com>,
Qais Yousef <qais.yousef@arm.com>,
Quentin Perret <qperret@google.com>,
Pavan Kondeti <pkondeti@codeaurora.org>,
Rik van Riel <riel@surriel.com>
Subject: Re: [PATCH 3/8] sched/fair: Tweak misfit-related capacity checks
Date: Fri, 05 Feb 2021 16:59:55 +0000 [thread overview]
Message-ID: <jhjv9b61md0.mognet@arm.com> (raw)
In-Reply-To: <CAKfTPtADn0X8=ENfvG5dhzM1KbTD+JCCoOm-i8=bVkh0ZBM2Xg@mail.gmail.com>
On 05/02/21 15:31, Vincent Guittot wrote:
> On Thu, 28 Jan 2021 at 19:32, Valentin Schneider
> <valentin.schneider@arm.com> wrote:
>>
>> During load-balance, groups classified as group_misfit_task are filtered
>> out if they do not pass
>>
>> group_smaller_max_cpu_capacity(<candidate group>, <local group>);
>
> group_smaller_max_cpu_capacity and group_smaller_max_cpu_capacity are
> removed in the next patch. Merge this and the next and directly remove
> them
>
OK.
>> @@ -8253,7 +8260,7 @@ check_cpu_capacity(struct rq *rq, struct sched_domain *sd)
>> static inline int check_misfit_status(struct rq *rq, struct sched_domain *sd)
>> {
>> return rq->misfit_task_load &&
>> - (rq->cpu_capacity_orig < rq->rd->max_cpu_capacity ||
>> + (capacity_greater(rq->rd->max_cpu_capacity, rq->cpu_capacity_orig) ||
>
> Why do you add a margin here whereas there was no margin before ?
>
Comparing capacities without any sort of filter can lead to ping-ponging
tasks around (capacity values very easily fluctuate by +/- 1, if not more).
I'm guilty of doing two things at once here: replace existing users, and
convert callsites that should be existing users. I can split the conversion
in a separate patch.
next prev parent reply other threads:[~2021-02-05 19:37 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-28 18:31 [PATCH 0/8] sched/fair: misfit task load-balance tweaks Valentin Schneider
2021-01-28 18:31 ` [PATCH 1/8] sched/fair: Clean up active balance nr_balance_failed trickery Valentin Schneider
2021-02-03 15:14 ` Qais Yousef
2021-02-03 18:42 ` Valentin Schneider
2021-02-04 15:05 ` Qais Yousef
2021-02-05 13:51 ` Vincent Guittot
2021-02-05 14:05 ` Valentin Schneider
2021-02-05 14:34 ` Vincent Guittot
2021-01-28 18:31 ` [PATCH 2/8] sched/fair: Add more sched_asym_cpucapacity static branch checks Valentin Schneider
2021-02-03 15:14 ` Qais Yousef
2021-02-09 8:42 ` Vincent Guittot
2021-01-28 18:31 ` [PATCH 3/8] sched/fair: Tweak misfit-related capacity checks Valentin Schneider
2021-02-03 15:15 ` Qais Yousef
2021-02-03 18:42 ` Valentin Schneider
2021-02-05 14:31 ` Vincent Guittot
2021-02-05 16:59 ` Valentin Schneider [this message]
2021-02-05 17:17 ` Vincent Guittot
2021-02-05 20:07 ` Valentin Schneider
2021-02-08 15:29 ` Vincent Guittot
2021-02-08 17:49 ` Valentin Schneider
2021-01-28 18:31 ` [PATCH 4/8] sched/fair: Use dst_cpu's capacity rather than group {min, max} capacity Valentin Schneider
2021-02-03 15:15 ` Qais Yousef
2021-01-28 18:31 ` [PATCH 5/8] sched/fair: Make check_misfit_status() only compare dynamic capacities Valentin Schneider
2021-02-03 15:15 ` Qais Yousef
2021-02-04 10:49 ` Dietmar Eggemann
2021-02-04 11:34 ` Valentin Schneider
2021-02-04 14:57 ` Dietmar Eggemann
2021-01-28 18:31 ` [PATCH 6/8] sched/fair: Filter out locally-unsolvable misfit imbalances Valentin Schneider
2021-02-03 15:16 ` Qais Yousef
2021-02-03 18:43 ` Valentin Schneider
2021-01-28 18:31 ` [PATCH 7/8] sched/fair: Attempt misfit active balance when migration_type != migrate_misfit Valentin Schneider
2021-02-03 15:16 ` Qais Yousef
2021-02-03 18:43 ` Valentin Schneider
2021-02-04 11:44 ` Dietmar Eggemann
2021-02-04 12:22 ` Valentin Schneider
2021-02-09 8:58 ` Vincent Guittot
2021-02-09 18:19 ` Valentin Schneider
2021-01-28 18:31 ` [PATCH 8/8] sched/fair: Relax task_hot() for misfit tasks Valentin Schneider
2021-02-03 15:17 ` Qais Yousef
2021-02-08 16:21 ` Vincent Guittot
2021-02-08 18:24 ` Valentin Schneider
2021-02-09 8:56 ` Vincent Guittot
2021-02-03 15:14 ` [PATCH 0/8] sched/fair: misfit task load-balance tweaks Qais Yousef
2021-02-03 18:43 ` Valentin Schneider
2021-02-04 12:03 ` Dietmar Eggemann
2021-02-04 12:36 ` Valentin Schneider
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