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From: khilman@deeprootsystems•com (Kevin Hilman)
To: linux-arm-kernel@lists•infradead.org
Subject: RT throttling and suspend/resume (was Re: [PATCH] i2c: omap: revert "i2c: omap: switch to threaded IRQ support")
Date: Fri, 19 Oct 2012 16:28:16 -0700	[thread overview]
Message-ID: <87a9vijb3j.fsf@deeprootsystems.com> (raw)
In-Reply-To: <1350655227.2768.11.camel@twins> (Peter Zijlstra's message of "Fri, 19 Oct 2012 16:00:27 +0200")

Peter Zijlstra <peterz@infradead•org> writes:

> On Thu, 2012-10-18 at 08:51 +0300, Felipe Balbi wrote:
>> > So the primary question remains: is RT runtime supposed to include the
>> > time spent suspended?  I suspect not. 
>> 
>> you might be right there, though we need Thomas or Peter to answer :-s 
>
> re, sorry both tglx and I have been traveling, he still is, I'm trying
> to play catch-up :-)

No worries, thanks for the help.

> Anyway, yeah I'm somewhat surprised the clock is 'running' when the
> machine isn't. From what I could gather, this is !x86 hardware, right?
>
> x86 explicitly makes sure our clocks are 'stopped' during suspend, see
> commit cd7240c0b900eb6d690ccee088a6c9b46dae815a.
>
> Can you do something similar for ARM? A quick look at
> arch/arm/kernel/sched_clock.c shows there's already suspend/resume
> hooks, do they do the wrong thing?

No, they do the right thing, but only if they're asked by the
SoC-specific code that registers a sched_clock.  Changing the SoC
specific code to use the 'needs_suspend' API gets things working
perfectly.

Thanks,

Kevin

  parent reply	other threads:[~2012-10-19 23:28 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-10-15  1:51 [PATCH] i2c: omap: revert "i2c: omap: switch to threaded IRQ support" Paul Walmsley
2012-10-15  7:16 ` Felipe Balbi
2012-10-15 15:05   ` Paul Walmsley
2012-10-16 12:58 ` Shubhrajyoti Datta
2012-10-16 13:33   ` Felipe Balbi
2012-10-16 13:37     ` Felipe Balbi
2012-10-16 21:39     ` RT throttling and suspend/resume (was Re: [PATCH] i2c: omap: revert "i2c: omap: switch to threaded IRQ support") Kevin Hilman
2012-10-17 14:00       ` Felipe Balbi
2012-10-17 14:41         ` Felipe Balbi
2012-10-17 23:06           ` Kevin Hilman
2012-10-18  5:51             ` Felipe Balbi
2012-10-19 14:00               ` Peter Zijlstra
2012-10-19 16:30                 ` Felipe Balbi
2012-10-19 23:28                 ` Kevin Hilman [this message]
2012-10-19 23:54                 ` Kevin Hilman
2012-10-22  9:52                   ` Peter Zijlstra
2012-10-22 16:47                     ` Kevin Hilman
2012-10-23  9:19                       ` Russell King - ARM Linux

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