From: Daniel Lezcano <daniel.lezcano@linaro.org>
To: Lianwei Wang <lianwei.wang@gmail.com>, Ingo Molnar <mingo@kernel.org>
Cc: rjw@rjwysocki.net, linux-pm@vger.kernel.org,
linux-kernel@vger.kernel.org, kbuild-all@01.org,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH RESEND] smp: make wake up idle cpus more generic
Date: Sat, 2 Apr 2016 15:10:40 +0200 [thread overview]
Message-ID: <56FFC4D0.4090609@linaro.org> (raw)
In-Reply-To: <CAJFUiJiHDmhPOnO6NYnTnvaXMaB6E3Jc9MSau-juq2BtHWq-Qg@mail.gmail.com>
On 04/02/2016 08:15 AM, Lianwei Wang wrote:
>>
>> * Lianwei Wang <lianwei.wang@gmail.com> wrote:
>>
>>> The wake_up_all_idle_cpus API always wake up all the online
>>> cpus, but sometimes we only want to wake up a set of cpus.
>>> Use a generic function to wake up a group of cpus that is
>>> specified by the cpumask parameter. This generic API can
>>> benefit to the cases that only need to wake up a set of
>>> cpus.
>>
>> What is the new user of this new argument to the wake-up call?
>>
>> Thanks,
>>
>> Ingo
>
> The ARM big.LITTLE arch is one of the users to use the new wake up
> call. Two clusters in these SoCs and each cluster has 2 or more CPUs.
> For some cases, we only need to wake up the cpus on one cluster, not
> all the cpus. The other cluster can keep in idle state to save power.
> Another use case is that for the threads/irqs that bind to some cpus,
> we also want to wake up the cpus that the threads/irqs bind to, and
> the other cpus can stay in idle state. I'm updating the pm_qos code to
> support binding the request to a set of cpus, and the
> cpuidle_latency_notify call can pass the cpumask parameter to the new
> wake-up call.
Hi Lianwei,
a quick suggestion : cpuidle_driver->cpumask
-- Daniel
--
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next prev parent reply other threads:[~2016-04-02 13:10 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-01 5:50 [PATCH RESEND] smp: make wake up idle cpus more generic Lianwei Wang
2016-04-01 7:07 ` Ingo Molnar
2016-04-02 6:15 ` Lianwei Wang
2016-04-02 13:10 ` Daniel Lezcano [this message]
2016-04-03 7:10 ` Lianwei Wang
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