From: Mel Gorman <mgorman@techsingularity.net>
To: Vincent Guittot <vincent.guittot@linaro.org>
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 4/4] sched/fair: Merge select_idle_core/cpu()
Date: Wed, 27 Jan 2021 13:21:21 +0000 [thread overview]
Message-ID: <20210127132121.GD3592@techsingularity.net> (raw)
In-Reply-To: <CAKfTPtB=vh0FzszeOS5ND4Voq3ck2AQgruF-4zC-K1hSSsbT_A@mail.gmail.com>
On Wed, Jan 27, 2021 at 02:07:50PM +0100, Vincent Guittot wrote:
> > @@ -6162,18 +6162,16 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t
> >
> > for_each_cpu_wrap(cpu, cpus, target) {
> > if (smt) {
> > - i = select_idle_core(p, cpu, cpus, &idle_cpu);
> > - if ((unsigned int)i < nr_cpumask_bits)
> > - return i;
> > + idle_cpu = select_idle_core(p, cpu, cpus, &idle_cpu);
>
> but how do you differentiate idle core (return value) and an idle cpu
> in the core set in &idle_cpu
>
> You will return as soon as a cpu is idle and before testing all cores
>
Bah, I'm sorry, I was context switching between multiple tasks and failed
to engage brain. I'll apply your hunk and resend. I don't think this
merits retesting as the saving of avoiding the intermeriate is marginal.
--
Mel Gorman
SUSE Labs
next prev parent reply other threads:[~2021-01-27 13:24 UTC|newest]
Thread overview: 14+ 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
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 [this message]
2021-01-27 13:26 ` Vincent Guittot
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 4/4] sched/fair: Merge select_idle_core/cpu() Mel Gorman
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