From: a.p.zijlstra@chello.nl (Peter Zijlstra)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 5/5] sched: cpu_power: enable ARCH_POWER
Date: Wed, 20 Jun 2012 11:19:39 +0200 [thread overview]
Message-ID: <1340183979.21745.78.camel@twins> (raw)
In-Reply-To: <CAKfTPtAdSMJ1RnDPDYZZ378QW9DUCKLA+oC3TWJD7v5KAkFitA@mail.gmail.com>
On Wed, 2012-06-20 at 11:11 +0200, Vincent Guittot wrote:
> On 19 June 2012 11:01, Yong Zhang <yong.zhang0@gmail.com> wrote:
> > On Tue, Jun 19, 2012 at 10:28:56AM +0200, Vincent Guittot wrote:
> >> Heteregeneous ARM platform uses arch_scale_freq_power function
> >> to reflect the relative capacity of each core
> >>
> >> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> >> ---
> >> kernel/sched/features.h | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/kernel/sched/features.h b/kernel/sched/features.h
> >> index de00a48..d98ae90 100644
> >> --- a/kernel/sched/features.h
> >> +++ b/kernel/sched/features.h
> >> @@ -42,7 +42,7 @@ SCHED_FEAT(CACHE_HOT_BUDDY, true)
> >> /*
> >> * Use arch dependent cpu power functions
> >> */
> >> -SCHED_FEAT(ARCH_POWER, false)
> >> +SCHED_FEAT(ARCH_POWER, true)
> >
> > Hmmm...seems we can remove this knob completely.
> >
>
> Peter,
>
> Do you prefer to keep it or remove it completely ?
I prefer to keep it, the 'we can remove it' is true for all feature
bits, they should never be twiddled in normal circumstances, its a debug
feature. As such it makes sense to allow disabling the arch cpu-power
fiddling.
WARNING: multiple messages have this Message-ID (diff)
From: Peter Zijlstra <a.p.zijlstra-/NLkJaSkS4VmR6Xm/wNWPw@public.gmane.org>
To: Vincent Guittot
<vincent.guittot-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: linaro-dev-cunTk1MwBs8s++Sfvej+rw@public.gmane.org,
devicetree-discuss-uLR06cmDAlY/bJ5BZ2RsiQ@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
rob.herring-bsGFqQB8/DxBDgjK7y7TUQ@public.gmane.org,
Yong Zhang <yong.zhang0-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
Subject: Re: [PATCH v2 5/5] sched: cpu_power: enable ARCH_POWER
Date: Wed, 20 Jun 2012 11:19:39 +0200 [thread overview]
Message-ID: <1340183979.21745.78.camel@twins> (raw)
In-Reply-To: <CAKfTPtAdSMJ1RnDPDYZZ378QW9DUCKLA+oC3TWJD7v5KAkFitA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
On Wed, 2012-06-20 at 11:11 +0200, Vincent Guittot wrote:
> On 19 June 2012 11:01, Yong Zhang <yong.zhang0-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:
> > On Tue, Jun 19, 2012 at 10:28:56AM +0200, Vincent Guittot wrote:
> >> Heteregeneous ARM platform uses arch_scale_freq_power function
> >> to reflect the relative capacity of each core
> >>
> >> Signed-off-by: Vincent Guittot <vincent.guittot-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
> >> ---
> >> kernel/sched/features.h | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/kernel/sched/features.h b/kernel/sched/features.h
> >> index de00a48..d98ae90 100644
> >> --- a/kernel/sched/features.h
> >> +++ b/kernel/sched/features.h
> >> @@ -42,7 +42,7 @@ SCHED_FEAT(CACHE_HOT_BUDDY, true)
> >> /*
> >> * Use arch dependent cpu power functions
> >> */
> >> -SCHED_FEAT(ARCH_POWER, false)
> >> +SCHED_FEAT(ARCH_POWER, true)
> >
> > Hmmm...seems we can remove this knob completely.
> >
>
> Peter,
>
> Do you prefer to keep it or remove it completely ?
I prefer to keep it, the 'we can remove it' is true for all feature
bits, they should never be twiddled in normal circumstances, its a debug
feature. As such it makes sense to allow disabling the arch cpu-power
fiddling.
WARNING: multiple messages have this Message-ID (diff)
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Yong Zhang <yong.zhang0@gmail.com>,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, linaro-dev@lists.linaro.org,
devicetree-discuss@lists.ozlabs.org, linux@arm.linux.org.uk,
grant.likely@secretlab.ca, rob.herring@calxeda.com
Subject: Re: [PATCH v2 5/5] sched: cpu_power: enable ARCH_POWER
Date: Wed, 20 Jun 2012 11:19:39 +0200 [thread overview]
Message-ID: <1340183979.21745.78.camel@twins> (raw)
In-Reply-To: <CAKfTPtAdSMJ1RnDPDYZZ378QW9DUCKLA+oC3TWJD7v5KAkFitA@mail.gmail.com>
On Wed, 2012-06-20 at 11:11 +0200, Vincent Guittot wrote:
> On 19 June 2012 11:01, Yong Zhang <yong.zhang0@gmail.com> wrote:
> > On Tue, Jun 19, 2012 at 10:28:56AM +0200, Vincent Guittot wrote:
> >> Heteregeneous ARM platform uses arch_scale_freq_power function
> >> to reflect the relative capacity of each core
> >>
> >> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> >> ---
> >> kernel/sched/features.h | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/kernel/sched/features.h b/kernel/sched/features.h
> >> index de00a48..d98ae90 100644
> >> --- a/kernel/sched/features.h
> >> +++ b/kernel/sched/features.h
> >> @@ -42,7 +42,7 @@ SCHED_FEAT(CACHE_HOT_BUDDY, true)
> >> /*
> >> * Use arch dependent cpu power functions
> >> */
> >> -SCHED_FEAT(ARCH_POWER, false)
> >> +SCHED_FEAT(ARCH_POWER, true)
> >
> > Hmmm...seems we can remove this knob completely.
> >
>
> Peter,
>
> Do you prefer to keep it or remove it completely ?
I prefer to keep it, the 'we can remove it' is true for all feature
bits, they should never be twiddled in normal circumstances, its a debug
feature. As such it makes sense to allow disabling the arch cpu-power
fiddling.
next prev parent reply other threads:[~2012-06-20 9:19 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-19 8:28 [PATCH v2 0/5] ARM: topology: set the capacity of each cores for big.LITTLE Vincent Guittot
2012-06-19 8:28 ` Vincent Guittot
2012-06-19 8:28 ` [PATCH v2 1/5] ARM: topology: Add arch_scale_freq_power function Vincent Guittot
2012-06-19 8:28 ` Vincent Guittot
2012-06-19 8:28 ` Vincent Guittot
[not found] ` <87fw9qhkl9.fsf@sejong.aot.lge.com>
2012-06-20 9:04 ` Vincent Guittot
2012-06-20 9:04 ` Vincent Guittot
2012-06-19 8:28 ` [PATCH v2 2/5] ARM: topology: factorize the update of sibling masks Vincent Guittot
2012-06-19 8:28 ` Vincent Guittot
2012-06-19 8:28 ` Vincent Guittot
2012-06-20 0:54 ` Namhyung Kim
2012-06-19 8:28 ` [PATCH v2 3/5] ARM: topology: Update cpu_power according to DT information Vincent Guittot
2012-06-19 8:28 ` Vincent Guittot
2012-06-19 8:28 ` Vincent Guittot
[not found] ` <877gv2hjhb.fsf@sejong.aot.lge.com>
2012-06-20 8:43 ` Vincent Guittot
2012-06-20 8:43 ` Vincent Guittot
2012-06-19 8:28 ` [PATCH v2 4/5] sched, x86: Remove broken power estimation Vincent Guittot
2012-06-19 8:28 ` Vincent Guittot
2012-06-19 8:28 ` Vincent Guittot
2012-06-19 8:28 ` [PATCH v2 5/5] sched: cpu_power: enable ARCH_POWER Vincent Guittot
2012-06-19 8:28 ` Vincent Guittot
2012-06-19 8:28 ` Vincent Guittot
2012-06-19 9:01 ` Yong Zhang
2012-06-19 9:01 ` Yong Zhang
2012-06-20 9:11 ` Vincent Guittot
2012-06-20 9:11 ` Vincent Guittot
2012-06-20 9:19 ` Peter Zijlstra [this message]
2012-06-20 9:19 ` Peter Zijlstra
2012-06-20 9:19 ` Peter Zijlstra
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