From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Saravana Kannan <skannan@codeaurora.org>,
Ingo Molnar <mingo@elte.hu>,
linaro-kernel@lists.linaro.org, Nicolas Pitre <nico@fluxnic.net>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Oleg Nesterov <oleg@redhat.com>,
cpufreq@vger.kernel.org, linux-kernel@vger.kernel.org,
Anton Vorontsov <anton.vorontsov@linaro.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Mike Chan <mike@android.com>, Dave Jones <davej@redhat.com>,
Todd Poynor <toddpoynor@google.com>,
kernel-team@android.com, linux-arm-kernel@lists.infradead.org,
Arjan Van De Ven <arjan@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH RFC 0/4] Scheduler idle notifiers and users
Date: Wed, 15 Feb 2012 17:09:07 +0100 [thread overview]
Message-ID: <1329322147.2293.145.camel@twins> (raw)
In-Reply-To: <20120215160028.GD27825@n2100.arm.linux.org.uk>
On Wed, 2012-02-15 at 16:00 +0000, Russell King - ARM Linux wrote:
>
> > A third possibility is to self-IPI and take it from there.. assuming
> > these platforms can actually self-IPI.
>
> Even if there was an IPI (not talking about SMP anyway) I'm not sure
> what good it would be. We can (and do) get an IRQ from the LCD
> controller when its shutdown is complete, but that would have to be
> somehow propagated back up to the cpufreq code. And the cpufreq code
> would have to know that the LCD controller was alive and therefore had
> to be waited for. All sounds rather yucky to me.
If can self-ipi from the scheduler context (which has IRQs disabled),
once you get to the ipi handler your scheduler locks are gone and you
can queue a worklet or wake some kthread to do all the sleeping stuff.
next prev parent reply other threads:[~2012-02-15 16:09 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
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 [this message]
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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