From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Mel Gorman <mgorman@techsingularity.net>,
Rik van Riel <riel@surriel.com>,
Thomas Gleixner <tglx@linutronix.de>,
Valentin Schneider <valentin.schneider@arm.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Michael Neuling <mikey@neuling.org>,
Gautham R Shenoy <ego@linux.vnet.ibm.com>,
Parth Shah <parth@linux.ibm.com>
Subject: Re: [PATCH] sched/fair: Prefer idle CPU to cache affinity
Date: Mon, 1 Mar 2021 22:38:49 +0530 [thread overview]
Message-ID: <20210301170849.GK2028034@linux.vnet.ibm.com> (raw)
In-Reply-To: <YD0K8Sal4KbxWD23@hirez.programming.kicks-ass.net>
* Peter Zijlstra <peterz@infradead.org> [2021-03-01 16:40:33]:
> On Fri, Feb 26, 2021 at 10:10:29PM +0530, Srikar Dronamraju wrote:
> > +static int prefer_idler_llc(int this_cpu, int prev_cpu, int sync)
> > +{
> > + struct sched_domain_shared *tsds, *psds;
> > + int pnr_busy, pllc_size, tnr_busy, tllc_size, diff;
> > +
> > + tsds = rcu_dereference(per_cpu(sd_llc_shared, this_cpu));
> > + tnr_busy = atomic_read(&tsds->nr_busy_cpus);
> > + tllc_size = per_cpu(sd_llc_size, this_cpu);
> > +
> > + psds = rcu_dereference(per_cpu(sd_llc_shared, prev_cpu));
> > + pnr_busy = atomic_read(&psds->nr_busy_cpus);
> > + pllc_size = per_cpu(sd_llc_size, prev_cpu);
> > +
>
> nr_busy_cpus is NO_HZ_COMMON So this code that consumes it should be
> too.
Thanks Peter, will take care of this along with other changes including
calling within rcu_read_lock and checking for tsds and psds after
rcu_dereference.
--
Thanks and Regards
Srikar Dronamraju
next prev parent reply other threads:[~2021-03-01 20:54 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-26 16:40 [PATCH] sched/fair: Prefer idle CPU to cache affinity Srikar Dronamraju
2021-02-27 19:56 ` Rik van Riel
2021-03-01 13:37 ` Srikar Dronamraju
2021-03-01 15:44 ` Peter Zijlstra
2021-03-01 17:06 ` Srikar Dronamraju
2021-03-01 17:18 ` Peter Zijlstra
2021-03-02 7:39 ` Srikar Dronamraju
2021-03-02 9:10 ` Peter Zijlstra
2021-03-02 10:05 ` Srikar Dronamraju
2021-03-01 15:40 ` Peter Zijlstra
2021-03-01 17:08 ` Srikar Dronamraju [this message]
2021-03-02 9:53 ` Dietmar Eggemann
2021-03-02 10:04 ` Srikar Dronamraju
2021-03-08 13:52 ` Vincent Guittot
2021-03-10 5:52 ` Srikar Dronamraju
2021-03-10 15:37 ` Vincent Guittot
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