From: Kevin Hilman <khilman-l0cyMroinI0@public.gmane.org>
To: Colin Cross <ccross-z5hGa2qSFaRBDgjK7y7TUQ@public.gmane.org>
Cc: Len Brown <len.brown-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Amit Kucheria
<amit.kucheria-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>,
linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-pm-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org,
linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Arjan van de Ven <arjan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
Subject: Re: [linux-pm] [PATCH 0/3] coupled cpuidle state support
Date: Wed, 14 Mar 2012 07:23:59 -0700 [thread overview]
Message-ID: <87mx7jjm68.fsf@ti.com> (raw)
In-Reply-To: <CAMbhsRRD2bdkcUZvScb-cF05e=R3h69bNVaTPFX4jBKBBOjuMg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> (Colin Cross's message of "Tue, 13 Mar 2012 17:47:20 -0700")
Colin Cross <ccross-z5hGa2qSFaRBDgjK7y7TUQ@public.gmane.org> writes:
> On Tue, Mar 13, 2012 at 5:28 PM, Colin Cross <ccross-z5hGa2qSFaRBDgjK7y7TUQ@public.gmane.org> wrote:
>> On Tue, Mar 13, 2012 at 4:52 PM, Kevin Hilman <khilman-l0cyMroinI0@public.gmane.org> wrote:
[...]
>>>
>>> Checking the ready_count seemed like an easy way to do this, but did you
>>> have any other mechanisms in mind for CPUs to communicate that they've
>>> exited/aborted?
>>
>> Why not set a flag from CPU1 when it exits the low power state, and
>> have CPU0 spin on the powerdomain register or the flag? You can then
>> use the parallel barrier function to ensure both cpus have seen the
>> flag and reset it to 0 before returning.
>
> I realized the parallel barrier helper was not included in the patch
> set I posted, it will be in the next patch set.
Do you have an ETA for the next patchset? I'll be glad to give it a
spin on OMAP4.
> Short version, no caller to cpuidle_coupled_parallel_barrier will
> return before all cpus in the coupled set have called it. It allows
> you to resynchronize the cpus after an abort to ensure they have all
> seen the abort flag before clearing it and returning, leaving
> everything in the correct state for the next idle attempt.
OK, this sounds like it will work well for what I need.
Kevin
WARNING: multiple messages have this Message-ID (diff)
From: khilman@ti.com (Kevin Hilman)
To: linux-arm-kernel@lists.infradead.org
Subject: [linux-pm] [PATCH 0/3] coupled cpuidle state support
Date: Wed, 14 Mar 2012 07:23:59 -0700 [thread overview]
Message-ID: <87mx7jjm68.fsf@ti.com> (raw)
In-Reply-To: <CAMbhsRRD2bdkcUZvScb-cF05e=R3h69bNVaTPFX4jBKBBOjuMg@mail.gmail.com> (Colin Cross's message of "Tue, 13 Mar 2012 17:47:20 -0700")
Colin Cross <ccross@android.com> writes:
> On Tue, Mar 13, 2012 at 5:28 PM, Colin Cross <ccross@android.com> wrote:
>> On Tue, Mar 13, 2012 at 4:52 PM, Kevin Hilman <khilman@ti.com> wrote:
[...]
>>>
>>> Checking the ready_count seemed like an easy way to do this, but did you
>>> have any other mechanisms in mind for CPUs to communicate that they've
>>> exited/aborted?
>>
>> Why not set a flag from CPU1 when it exits the low power state, and
>> have CPU0 spin on the powerdomain register or the flag? ?You can then
>> use the parallel barrier function to ensure both cpus have seen the
>> flag and reset it to 0 before returning.
>
> I realized the parallel barrier helper was not included in the patch
> set I posted, it will be in the next patch set.
Do you have an ETA for the next patchset? I'll be glad to give it a
spin on OMAP4.
> Short version, no caller to cpuidle_coupled_parallel_barrier will
> return before all cpus in the coupled set have called it. It allows
> you to resynchronize the cpus after an abort to ensure they have all
> seen the abort flag before clearing it and returning, leaving
> everything in the correct state for the next idle attempt.
OK, this sounds like it will work well for what I need.
Kevin
WARNING: multiple messages have this Message-ID (diff)
From: Kevin Hilman <khilman@ti.com>
To: Colin Cross <ccross@android.com>
Cc: Len Brown <len.brown@intel.com>,
linux-kernel@vger.kernel.org,
Amit Kucheria <amit.kucheria@linaro.org>,
linux-tegra@vger.kernel.org, linux-pm@lists.linux-foundation.org,
linux-omap@vger.kernel.org,
Arjan van de Ven <arjan@linux.intel.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [linux-pm] [PATCH 0/3] coupled cpuidle state support
Date: Wed, 14 Mar 2012 07:23:59 -0700 [thread overview]
Message-ID: <87mx7jjm68.fsf@ti.com> (raw)
In-Reply-To: <CAMbhsRRD2bdkcUZvScb-cF05e=R3h69bNVaTPFX4jBKBBOjuMg@mail.gmail.com> (Colin Cross's message of "Tue, 13 Mar 2012 17:47:20 -0700")
Colin Cross <ccross@android.com> writes:
> On Tue, Mar 13, 2012 at 5:28 PM, Colin Cross <ccross@android.com> wrote:
>> On Tue, Mar 13, 2012 at 4:52 PM, Kevin Hilman <khilman@ti.com> wrote:
[...]
>>>
>>> Checking the ready_count seemed like an easy way to do this, but did you
>>> have any other mechanisms in mind for CPUs to communicate that they've
>>> exited/aborted?
>>
>> Why not set a flag from CPU1 when it exits the low power state, and
>> have CPU0 spin on the powerdomain register or the flag? You can then
>> use the parallel barrier function to ensure both cpus have seen the
>> flag and reset it to 0 before returning.
>
> I realized the parallel barrier helper was not included in the patch
> set I posted, it will be in the next patch set.
Do you have an ETA for the next patchset? I'll be glad to give it a
spin on OMAP4.
> Short version, no caller to cpuidle_coupled_parallel_barrier will
> return before all cpus in the coupled set have called it. It allows
> you to resynchronize the cpus after an abort to ensure they have all
> seen the abort flag before clearing it and returning, leaving
> everything in the correct state for the next idle attempt.
OK, this sounds like it will work well for what I need.
Kevin
next prev parent reply other threads:[~2012-03-14 14:23 UTC|newest]
Thread overview: 114+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-21 0:09 [PATCH 0/3] coupled cpuidle state support Colin Cross
2011-12-21 0:09 ` Colin Cross
2011-12-21 0:09 ` Colin Cross
2011-12-21 0:09 ` [PATCH 1/3] cpuidle: refactor out cpuidle_enter_state Colin Cross
2011-12-21 0:09 ` Colin Cross
2011-12-21 0:09 ` Colin Cross
2012-01-04 14:08 ` Jean Pihet
2012-01-04 14:08 ` [linux-pm] " Jean Pihet
2012-01-04 14:08 ` Jean Pihet
2011-12-21 0:09 ` [PATCH 2/3] cpuidle: fix error handling in __cpuidle_register_device Colin Cross
[not found] ` <1324426147-16735-1-git-send-email-ccross-z5hGa2qSFaRBDgjK7y7TUQ@public.gmane.org>
2011-12-21 0:09 ` Colin Cross
2011-12-21 0:09 ` Colin Cross
2011-12-21 0:09 ` Colin Cross
2011-12-21 0:09 ` [PATCH 3/3] cpuidle: add support for states that affect multiple cpus Colin Cross
2011-12-21 0:09 ` Colin Cross
2011-12-21 0:09 ` Colin Cross
2011-12-21 9:02 ` [PATCH 0/3] coupled cpuidle state support Arjan van de Ven
2011-12-21 9:02 ` Arjan van de Ven
2011-12-21 9:02 ` Arjan van de Ven
2011-12-21 9:40 ` Colin Cross
[not found] ` <4EF1A0B4.5080307-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2011-12-21 9:40 ` Colin Cross
2011-12-21 9:40 ` Colin Cross
2011-12-21 9:40 ` Colin Cross
2011-12-21 9:44 ` Arjan van de Ven
2011-12-21 9:44 ` Arjan van de Ven
2011-12-21 9:44 ` Arjan van de Ven
[not found] ` <4EF1AA8A.8060304-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2011-12-21 9:55 ` Colin Cross
2011-12-21 9:55 ` Colin Cross
2011-12-21 9:55 ` Colin Cross
2011-12-21 12:12 ` Arjan van de Ven
2011-12-21 12:12 ` Arjan van de Ven
2011-12-21 19:05 ` Colin Cross
2011-12-21 19:05 ` Colin Cross
2011-12-21 19:05 ` Colin Cross
2011-12-21 19:36 ` Arjan van de Ven
[not found] ` <CAMbhsRRnKoR3YPWrZzVynVe+dcuU5v0siYvmp2vbBcS1hquC7Q-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2011-12-21 19:36 ` Arjan van de Ven
2011-12-21 19:36 ` Arjan van de Ven
2011-12-21 19:36 ` Arjan van de Ven
2011-12-21 19:42 ` Colin Cross
2011-12-21 19:42 ` [linux-pm] " Colin Cross
2011-12-21 19:42 ` Colin Cross
2011-12-22 8:35 ` Shilimkar, Santosh
[not found] ` <CAMbhsRSPCo9MSGp57Fv0sRdYUFcdwx8jEz1-CfX8LdKf8X4MVg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2011-12-22 8:35 ` [linux-pm] " Shilimkar, Santosh
2011-12-22 8:35 ` Shilimkar, Santosh
2011-12-22 8:35 ` Shilimkar, Santosh
2011-12-22 8:53 ` Arjan van de Ven
2011-12-22 8:53 ` [linux-pm] " Arjan van de Ven
2011-12-22 8:53 ` Arjan van de Ven
2011-12-22 9:30 ` Shilimkar, Santosh
2011-12-22 9:30 ` Shilimkar, Santosh
2011-12-22 9:30 ` Shilimkar, Santosh
2011-12-22 21:20 ` Colin Cross
[not found] ` <4EF2F01E.8060307-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2011-12-22 21:20 ` [linux-pm] " Colin Cross
2011-12-22 21:20 ` Colin Cross
2011-12-22 21:20 ` Colin Cross
[not found] ` <4EF1CD49.9020800-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
2012-03-14 0:39 ` Colin Cross
2012-03-14 0:39 ` Colin Cross
2012-03-14 0:39 ` Colin Cross
2011-12-21 12:12 ` Arjan van de Ven
2011-12-21 9:55 ` Colin Cross
2012-01-04 0:41 ` Kevin Hilman
2012-01-04 0:41 ` Kevin Hilman
2012-01-04 0:41 ` Kevin Hilman
2012-01-04 17:27 ` Shilimkar, Santosh
2012-01-04 17:27 ` Shilimkar, Santosh
2012-01-04 17:27 ` Shilimkar, Santosh
2012-01-20 8:46 ` Daniel Lezcano
2012-01-20 8:46 ` Daniel Lezcano
2012-01-20 8:46 ` Daniel Lezcano
2012-01-20 20:40 ` Colin Cross
2012-01-20 20:40 ` Colin Cross
2012-01-20 20:40 ` Colin Cross
2012-01-25 14:04 ` Daniel Lezcano
2012-01-25 14:04 ` Daniel Lezcano
2012-01-31 14:13 ` Daniel Lezcano
2012-01-31 14:13 ` Daniel Lezcano
[not found] ` <CAMbhsRTbVqV6p0py9NGZrpFPf2yvp-B0dr+o-m7qbdja_-Lfzw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-01-27 8:54 ` [linux-pm] " Vincent Guittot
2012-01-27 8:54 ` Vincent Guittot
2012-01-27 8:54 ` Vincent Guittot
2012-01-27 17:32 ` Colin Cross
2012-01-27 17:32 ` Colin Cross
2012-01-27 17:32 ` Colin Cross
[not found] ` <CAMbhsRQYVXTZ2pX4mBrM6=SyGTqn_GY8xsW4rt_e21zerEzctA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-02-01 12:13 ` Vincent Guittot
2012-02-01 12:13 ` Vincent Guittot
2012-02-01 12:13 ` Vincent Guittot
2012-02-01 14:59 ` Lorenzo Pieralisi
2012-02-01 14:59 ` [linux-pm] " Lorenzo Pieralisi
2012-02-01 14:59 ` Lorenzo Pieralisi
2012-02-01 17:30 ` Colin Cross
2012-02-01 17:30 ` Colin Cross
2012-02-01 17:30 ` Colin Cross
2012-02-01 18:07 ` Lorenzo Pieralisi
2012-02-01 18:07 ` [linux-pm] " Lorenzo Pieralisi
2012-02-01 18:07 ` Lorenzo Pieralisi
2012-02-03 1:19 ` Colin Cross
2012-02-03 1:19 ` [linux-pm] " Colin Cross
2012-02-03 1:19 ` Colin Cross
2012-03-13 23:52 ` Kevin Hilman
2012-03-13 23:52 ` Kevin Hilman
[not found] ` <8762e8kqi6.fsf-l0cyMroinI0@public.gmane.org>
2012-03-14 0:28 ` Colin Cross
2012-03-14 0:28 ` Colin Cross
2012-03-14 0:28 ` Colin Cross
2012-03-14 0:47 ` Colin Cross
2012-03-14 0:47 ` Colin Cross
2012-03-14 0:47 ` Colin Cross
[not found] ` <CAMbhsRRD2bdkcUZvScb-cF05e=R3h69bNVaTPFX4jBKBBOjuMg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2012-03-14 14:23 ` Kevin Hilman [this message]
2012-03-14 14:23 ` [linux-pm] " Kevin Hilman
2012-03-14 14:23 ` Kevin Hilman
2012-03-14 2:04 ` Arjan van de Ven
2012-03-14 2:04 ` Arjan van de Ven
2012-03-14 2:04 ` Arjan van de Ven
2012-03-14 2:21 ` Colin Cross
2012-03-14 2:21 ` Colin Cross
2012-03-14 2:21 ` Colin Cross
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