From: Peter Zijlstra <peterz@infradead.org>
To: Joel Fernandes <joelaf@google.com>
Cc: Rohit Jain <rohit.k.jain@oracle.com>,
Ingo Molnar <mingo@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
steven.sistare@oracle.com, dhaval.giani@oracle.com,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Vincent Guittot <vincent.guittot@linaro.org>,
Morten Rasmussen <morten.rasmussen@arm.com>,
"Cc: EAS Dev" <eas-dev@lists.linaro.org>
Subject: Re: [RESEND PATCH] sched/fair: consider RT/IRQ pressure in select_idle_sibling
Date: Fri, 9 Feb 2018 13:37:04 +0100 [thread overview]
Message-ID: <20180209123704.GN25201@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <CAJWu+opnwHQm8p6LnFRpfmQ+rkPgeGUWkV_imemvMqzg2WGB_Q@mail.gmail.com>
On Mon, Feb 05, 2018 at 10:50:41PM -0800, Joel Fernandes wrote:
> That's Ok with me. Just that I remember Peter messing with this path
> and that it was expensive to scan too much for some systems. The other
> thing is you're really doing to do a "fail safe" as you call it search
> here with SIS_PROP set. Do you see a difference in perf when doing the
> same approach as you took in select_idle_core?
>
> Peter, are you with the approach Rohit has adopted to pick best
> capacity idle CPU in select_idle_cpu? I guess nr--; will bail out
> early if we have SIS_PROP set, incase the scan cost gets too much but
> then again we might end scanning too few CPUs.
_IF_ you want to consider capacity, I don't think there's much else you
can do. And yes, nr-- might have to save the day more often.
next prev parent reply other threads:[~2018-02-09 12:37 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-29 23:27 Rohit Jain
2018-01-30 3:39 ` Joel Fernandes
2018-01-30 19:47 ` Rohit Jain
2018-01-31 1:57 ` Joel Fernandes
2018-01-31 17:50 ` Rohit Jain
2018-02-06 6:50 ` Joel Fernandes
2018-02-06 6:51 ` Joel Fernandes
2018-02-06 17:41 ` Rohit Jain
2018-02-09 12:37 ` Peter Zijlstra [this message]
2018-02-06 6:42 ` Joel Fernandes
2018-02-06 17:36 ` Rohit Jain
2018-02-09 12:35 ` Peter Zijlstra
2018-02-09 12:53 ` Peter Zijlstra
2018-02-09 15:46 ` Dietmar Eggemann
2018-02-09 22:05 ` Rohit Jain
2018-02-14 9:11 ` Dietmar Eggemann
2018-02-09 22:17 ` Rohit Jain
2018-03-10 20:41 ` Rohit Jain
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