From: "Joel Fernandes (Google)" <joel.opensrc@gmail.com>
To: Patrick Bellasi <patrick.bellasi@arm.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-pm@vger.kernel.org, Ingo Molnar <mingo@redhat.com>,
Peter Zijlstra <peterz@infradead.org>, Tejun Heo <tj@kernel.org>,
Joel Fernandes <joelaf@google.com>
Subject: Re: [RFC v3 1/5] sched/core: add capacity constraints to CPU controller
Date: Mon, 13 Mar 2017 03:46:13 -0700 [thread overview]
Message-ID: <CAEi0qNkAK_3a_2x9BgvyEC+bFvckGFoQX1fjFba6boC1ws_R5w@mail.gmail.com> (raw)
In-Reply-To: <1488292722-19410-2-git-send-email-patrick.bellasi@arm.com>
On Tue, Feb 28, 2017 at 6:38 AM, Patrick Bellasi
<patrick.bellasi@arm.com> wrote:
> The CPU CGroup controller allows to assign a specified (maximum)
> bandwidth to tasks within a group, however it does not enforce any
> constraint on how such bandwidth can be consumed.
> With the integration of schedutil, the scheduler has now the proper
> information about a task to select the most suitable frequency to
> satisfy tasks needs.
[..]
> +static u64 cpu_capacity_min_read_u64(struct cgroup_subsys_state *css,
> + struct cftype *cft)
> +{
> + struct task_group *tg;
> + u64 min_capacity;
> +
> + rcu_read_lock();
> + tg = css_tg(css);
> + min_capacity = tg->cap_clamp[CAP_CLAMP_MIN];
Shouldn't the cap_clamp be accessed with READ_ONCE (and WRITE_ONCE in
the write path) to avoid load-tearing?
Thanks,
Joel
next prev parent reply other threads:[~2017-03-13 10:46 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-28 14:38 [RFC v3 0/5] Add capacity capping support to the CPU controller Patrick Bellasi
2017-02-28 14:38 ` [RFC v3 1/5] sched/core: add capacity constraints to " Patrick Bellasi
2017-03-13 10:46 ` Joel Fernandes (Google) [this message]
2017-03-15 11:20 ` Patrick Bellasi
2017-03-15 13:20 ` Joel Fernandes
2017-03-15 16:10 ` Paul E. McKenney
2017-03-15 16:44 ` Patrick Bellasi
2017-03-15 17:24 ` Paul E. McKenney
2017-03-15 17:57 ` Patrick Bellasi
2017-03-20 17:15 ` Tejun Heo
2017-03-20 17:36 ` Tejun Heo
2017-03-20 18:08 ` Patrick Bellasi
2017-03-23 0:28 ` Joel Fernandes (Google)
2017-03-23 10:32 ` Patrick Bellasi
2017-03-23 16:01 ` Tejun Heo
2017-03-23 18:15 ` Patrick Bellasi
2017-03-23 18:39 ` Tejun Heo
2017-03-24 6:37 ` Joel Fernandes (Google)
2017-03-24 15:00 ` Tejun Heo
2017-03-30 21:13 ` Paul Turner
2017-03-24 7:02 ` Joel Fernandes (Google)
2017-03-30 21:15 ` Paul Turner
2017-04-01 16:25 ` Patrick Bellasi
2017-02-28 14:38 ` [RFC v3 2/5] sched/core: track CPU's capacity_{min,max} Patrick Bellasi
2017-02-28 14:38 ` [RFC v3 3/5] sched/core: sync capacity_{min,max} between slow and fast paths Patrick Bellasi
2017-02-28 14:38 ` [RFC v3 4/5] sched/{core,cpufreq_schedutil}: add capacity clamping for FAIR tasks Patrick Bellasi
2017-02-28 14:38 ` [RFC v3 5/5] sched/{core,cpufreq_schedutil}: add capacity clamping for RT/DL tasks Patrick Bellasi
2017-03-13 10:08 ` Joel Fernandes (Google)
2017-03-15 11:40 ` Patrick Bellasi
2017-03-15 12:59 ` Joel Fernandes
2017-03-15 14:44 ` Juri Lelli
2017-03-15 16:13 ` Joel Fernandes
2017-03-15 16:24 ` Juri Lelli
2017-03-15 23:40 ` Joel Fernandes
2017-03-16 11:16 ` Juri Lelli
2017-03-16 12:27 ` Patrick Bellasi
2017-03-16 12:44 ` Juri Lelli
2017-03-16 16:58 ` Joel Fernandes
2017-03-16 17:17 ` Juri Lelli
2017-03-15 11:41 ` [RFC v3 0/5] Add capacity capping support to the CPU controller Rafael J. Wysocki
2017-03-15 12:59 ` Patrick Bellasi
2017-03-16 1:04 ` Rafael J. Wysocki
2017-03-16 3:15 ` Joel Fernandes
2017-03-20 22:51 ` Rafael J. Wysocki
2017-03-21 11:01 ` Patrick Bellasi
2017-03-24 23:52 ` Rafael J. Wysocki
2017-03-16 12:23 ` Patrick Bellasi
2017-03-20 14:51 ` Tejun Heo
2017-03-20 17:22 ` Patrick Bellasi
2017-04-10 7:36 ` Peter Zijlstra
2017-04-11 17:58 ` Patrick Bellasi
2017-04-12 12:10 ` Peter Zijlstra
2017-04-12 13:55 ` Patrick Bellasi
2017-04-12 15:37 ` Peter Zijlstra
2017-04-13 11:33 ` Patrick Bellasi
2017-04-12 12:15 ` Peter Zijlstra
2017-04-12 13:34 ` Patrick Bellasi
2017-04-12 14:41 ` Peter Zijlstra
2017-04-12 12:22 ` Peter Zijlstra
2017-04-12 13:24 ` Patrick Bellasi
2017-04-12 12:48 ` Peter Zijlstra
2017-04-12 13:27 ` Patrick Bellasi
2017-04-12 14:34 ` Peter Zijlstra
2017-04-12 14:43 ` Patrick Bellasi
2017-04-12 16:14 ` Peter Zijlstra
2017-04-13 10:34 ` Patrick Bellasi
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