From: Peter Zijlstra <peterz@infradead.org>
To: Patrick Bellasi <patrick.bellasi@arm.com>
Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
Ingo Molnar <mingo@redhat.com>,
"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
Viresh Kumar <viresh.kumar@linaro.org>,
Vincent Guittot <vincent.guittot@linaro.org>,
Paul Turner <pjt@google.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Morten Rasmussen <morten.rasmussen@arm.com>,
Juri Lelli <juri.lelli@redhat.com>, Todd Kjos <tkjos@android.com>,
Joel Fernandes <joelaf@google.com>
Subject: Re: [PATCH v2 2/4] sched/fair: add util_est on top of PELT
Date: Wed, 13 Dec 2017 17:05:37 +0100 [thread overview]
Message-ID: <20171213160537.uqa423dyt5wrpgll@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20171205171018.9203-3-patrick.bellasi@arm.com>
On Tue, Dec 05, 2017 at 05:10:16PM +0000, Patrick Bellasi wrote:
> + if (cfs_rq->nr_running > 0) {
> + util_est = cfs_rq->util_est_runnable;
> + util_est -= task_util_est(p);
> + if (util_est < 0)
> + util_est = 0;
> + cfs_rq->util_est_runnable = util_est;
> + } else {
I'm thinking that's an explicit load-store to avoid intermediate values
landing in cfs_rq->util_esp_runnable, right?
That would need READ_ONCE() / WRITE_ONCE() I think, without that the
compiler is free to munge the lot together.
next prev parent reply other threads:[~2017-12-13 16:05 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-05 17:10 [PATCH v2 0/4] Utilization estimation (util_est) for FAIR tasks Patrick Bellasi
2017-12-05 17:10 ` [PATCH v2 1/4] sched/fair: always used unsigned long for utilization Patrick Bellasi
2017-12-06 8:56 ` Vincent Guittot
2018-01-10 12:14 ` [tip:sched/core] sched/fair: Use 'unsigned long' for utilization, consistently tip-bot for Patrick Bellasi
2017-12-05 17:10 ` [PATCH v2 2/4] sched/fair: add util_est on top of PELT Patrick Bellasi
2017-12-13 16:05 ` Peter Zijlstra [this message]
2017-12-15 14:02 ` Patrick Bellasi
2017-12-15 14:07 ` Peter Zijlstra
2017-12-15 15:22 ` Patrick Bellasi
2017-12-13 16:16 ` Peter Zijlstra
2017-12-15 12:14 ` Patrick Bellasi
2017-12-15 12:53 ` Peter Zijlstra
2017-12-15 15:41 ` Patrick Bellasi
2017-12-20 8:57 ` Peter Zijlstra
2017-12-20 9:02 ` Peter Zijlstra
2017-12-13 16:19 ` Peter Zijlstra
2017-12-13 16:36 ` Patrick Bellasi
2017-12-13 17:03 ` Peter Zijlstra
2017-12-15 12:03 ` Patrick Bellasi
2017-12-15 12:58 ` Peter Zijlstra
2017-12-05 17:10 ` [PATCH v2 3/4] sched/fair: use util_est in LB and WU paths Patrick Bellasi
2017-12-05 17:10 ` [PATCH v2 4/4] sched/cpufreq_schedutil: use util_est for OPP selection Patrick Bellasi
2017-12-16 2:35 ` Rafael J. Wysocki
2017-12-18 10:48 ` Patrick Bellasi
2017-12-13 16:03 ` [PATCH v2 0/4] Utilization estimation (util_est) for FAIR tasks Peter Zijlstra
2017-12-13 16:23 ` Patrick Bellasi
2017-12-13 17:56 ` Mike Galbraith
2017-12-15 16:13 ` Patrick Bellasi
2017-12-15 20:23 ` Mike Galbraith
2017-12-16 6:37 ` Mike Galbraith
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