From: Vincent Guittot <vincent.guittot@linaro.org>
To: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Li Aubrey <aubrey.li@linux.intel.com>,
Qais Yousef <qais.yousef@arm.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 2/4] sched/fair: Move avg_scan_cost calculations under SIS_PROP
Date: Wed, 27 Jan 2021 11:39:23 +0100 [thread overview]
Message-ID: <CAKfTPtCuUdr+Q++MbbVafEx9wEoJYQGm9maoJ4RCX7ny+=qA5w@mail.gmail.com> (raw)
In-Reply-To: <20210125085909.4600-3-mgorman@techsingularity.net>
On Mon, 25 Jan 2021 at 09:59, Mel Gorman <mgorman@techsingularity.net> wrote:
>
> As noted by Vincent Guittot, avg_scan_costs are calculated for SIS_PROP
> even if SIS_PROP is disabled. Move the time calculations under a SIS_PROP
> check and while we are at it, exclude the cost of initialising the CPU
> mask from the average scan cost.
>
> Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
> ---
> kernel/sched/fair.c | 14 ++++++++------
> 1 file changed, 8 insertions(+), 6 deletions(-)
>
> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
> index 9f5682aeda2e..c8d8e185cf3b 100644
> --- a/kernel/sched/fair.c
> +++ b/kernel/sched/fair.c
> @@ -6153,6 +6153,8 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t
> if (!this_sd)
> return -1;
>
> + cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr);
> +
> if (sched_feat(SIS_PROP)) {
> u64 avg_cost, avg_idle, span_avg;
>
> @@ -6168,11 +6170,9 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t
> nr = div_u64(span_avg, avg_cost);
> else
> nr = 4;
> - }
> -
> - time = cpu_clock(this);
>
> - cpumask_and(cpus, sched_domain_span(sd), p->cpus_ptr);
> + time = cpu_clock(this);
> + }
>
> for_each_cpu_wrap(cpu, cpus, target) {
> if (!--nr)
> @@ -6181,8 +6181,10 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t
> break;
> }
>
> - time = cpu_clock(this) - time;
> - update_avg(&this_sd->avg_scan_cost, time);
> + if (sched_feat(SIS_PROP)) {
> + time = cpu_clock(this) - time;
> + update_avg(&this_sd->avg_scan_cost, time);
> + }
>
> return cpu;
> }
> --
> 2.26.2
>
next prev parent reply other threads:[~2021-01-27 10:46 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-25 8:59 [PATCH v4 0/4] Scan for an idle sibling in a single pass Mel Gorman
2021-01-25 8:59 ` [PATCH 1/4] sched/fair: Remove SIS_AVG_CPU Mel Gorman
2021-01-25 8:59 ` [PATCH 2/4] sched/fair: Move avg_scan_cost calculations under SIS_PROP Mel Gorman
2021-01-27 10:39 ` Vincent Guittot [this message]
2021-01-25 8:59 ` [PATCH 3/4] sched/fair: Remove select_idle_smt() Mel Gorman
2021-01-27 10:39 ` Vincent Guittot
2021-02-17 13:17 ` [tip: sched/core] " tip-bot2 for Mel Gorman
2021-01-25 8:59 ` [PATCH 4/4] sched/fair: Merge select_idle_core/cpu() Mel Gorman
2021-01-27 10:43 ` Vincent Guittot
2021-01-27 12:02 ` Mel Gorman
2021-01-27 13:07 ` Vincent Guittot
2021-01-27 13:21 ` Mel Gorman
2021-01-27 13:26 ` Vincent Guittot
-- strict thread matches above, loose matches on Subject: below --
2021-01-27 13:51 [PATCH v5 0/4] Scan for an idle sibling in a single pass Mel Gorman
2021-01-27 13:52 ` [PATCH 2/4] sched/fair: Move avg_scan_cost calculations under SIS_PROP Mel Gorman
2020-12-08 15:34 [PATCH 0/4] Reduce scanning of runqueues in select_idle_sibling Mel Gorman
2020-12-08 15:34 ` [PATCH 2/4] sched/fair: Move avg_scan_cost calculations under SIS_PROP Mel Gorman
2020-12-08 16:03 ` Vincent Guittot
2020-12-08 16:30 ` Mel Gorman
2020-12-09 5:28 ` Li, Aubrey
2020-12-09 9:05 ` Mel Gorman
2020-12-09 11:07 ` Li, Aubrey
2020-12-09 11:33 ` Mel Gorman
2020-12-10 5:18 ` Li, Aubrey
2020-12-10 9:32 ` Mel Gorman
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