From: Mark Brown <broonie@opensource.wolfsonmicro.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Saravana Kannan <skannan@codeaurora.org>,
Ingo Molnar <mingo@elte.hu>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Todd Poynor <toddpoynor@google.com>,
Russell King <linux@arm.linux.org.uk>,
Nicolas Pitre <nico@fluxnic.net>, Oleg Nesterov <oleg@redhat.com>,
cpufreq@vger.kernel.org, linux-kernel@vger.kernel.org,
Anton Vorontsov <anton.vorontsov@linaro.org>,
linaro-kernel@lists.linaro.org, Mike Chan <mike@android.com>,
Dave Jones <davej@redhat.com>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
kernel-team@android.com, linux-arm-kernel@lists.infradead.org,
Arjan Van De Ven <arjan@infradead.org>
Subject: Re: [PATCH RFC 0/4] Scheduler idle notifiers and users
Date: Wed, 15 Feb 2012 08:04:38 -0800 [thread overview]
Message-ID: <20120215160437.GD2996@opensource.wolfsonmicro.com> (raw)
In-Reply-To: <1329313084.2293.105.camel@twins>
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On Wed, Feb 15, 2012 at 02:38:04PM +0100, Peter Zijlstra wrote:
> On Sat, 2012-02-11 at 15:33 +0000, Mark Brown wrote:
> > There's use cases for having this
> > stuff offloaded but if you're not doing that stuff then why deal with
> > the complication of designing the hardware?
> Because doing it in software is more expensive?
> Penny-wise pound-foolish like thing.. you make the software requirements
> more complex, which results in more bugs (more cost in debugging), more
> runtime (for doing the 'software' thing), less power savings.
> Esp since all this uC/system-controller stuff is already available and
> validated.
It's really not - like I say most of the times people have tried to
deploy this on embedded systems it's just made everyone more miserable
and typically winds up getting turned off or bypassed. The PMICs are
much more decoupled from the CPUs and the power control on the SoCs is
more fine grained than you seem to see in the desktop market. There's
software effort but people are willing to spend that for microamps and
all other things being equal they'd typically rather spend it in the
software stack they're already working with rather than in a separate
stack for a microcontroller.
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next prev parent reply other threads:[~2012-02-15 16:04 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-08 1:39 [PATCH RFC 0/4] Scheduler idle notifiers and users Anton Vorontsov
2012-02-08 1:41 ` [PATCH 1/4] sched: Introduce idle notifiers API Anton Vorontsov
2012-02-08 1:43 ` [PATCH 2/4] sched: Wire up idle notifiers Anton Vorontsov
2012-02-08 1:44 ` [PATCH 3/4] cpufreq: New 'interactive' governor Anton Vorontsov
2012-02-08 23:00 ` Vincent Guittot
2012-02-09 0:32 ` Anton Vorontsov
2012-02-08 1:44 ` [PATCH 4/4] ARM: Move leds idle start/stop calls to sched idle notifiers Anton Vorontsov
2012-02-08 3:05 ` [PATCH RFC 0/4] Scheduler idle notifiers and users Peter Zijlstra
2012-02-08 20:23 ` Dave Jones
2012-02-08 21:33 ` Benjamin Herrenschmidt
2012-02-09 7:51 ` Ingo Molnar
2012-02-11 3:15 ` Saravana Kannan
2012-02-11 14:39 ` Mark Brown
2012-02-11 14:53 ` Peter Zijlstra
2012-02-11 15:33 ` Mark Brown
2012-02-15 13:38 ` Peter Zijlstra
2012-02-15 16:04 ` Mark Brown [this message]
2012-02-12 21:33 ` Benjamin Herrenschmidt
2012-02-11 14:45 ` Ingo Molnar
2012-02-14 23:20 ` Saravana Kannan
2012-02-15 13:38 ` Peter Zijlstra
2012-02-15 14:02 ` Russell King - ARM Linux
2012-02-15 15:01 ` Peter Zijlstra
2012-02-15 16:00 ` Russell King - ARM Linux
2012-02-15 16:09 ` Peter Zijlstra
2012-02-16 3:31 ` Benjamin Herrenschmidt
2012-02-16 10:14 ` Peter Zijlstra
2012-02-17 9:00 ` Dominik Brodowski
2012-02-20 11:03 ` Peter Zijlstra
2012-02-21 12:38 ` Pantelis Antoniou
2012-02-21 12:56 ` Peter Zijlstra
2012-02-21 13:31 ` Pantelis Antoniou
2012-02-21 14:52 ` Amit Kucheria
2012-02-21 17:06 ` Pantelis Antoniou
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