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Date: Fri, 29 May 2009 08:37:16 +0900
From: Paul Mundt <lethal@linux-sh.org>
To: Daniel Walker <dwalker@fifo99.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
       Thomas Gleixner <tglx@linutronix.de>,
       Linus Walleij <linus.ml.walleij@gmail.com>, Ingo Molnar <mingo@elte.hu>,
       Andrew Victor <linux@maxim.org.za>,
       Haavard Skinnemoen <hskinnemoen@atmel.com>,
       Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org,
       linux-sh@vger.kernel.org, linux-arm-kernel@lists.arm.linux.org.uk,
       John Stultz <johnstul@linux.vnet.ibm.com>
Subject: Re: [PATCH] sched: Support current clocksource handling in fallback sched_clock().
Message-ID: <20090528233716.GB1122@linux-sh.org>
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	Andrew Morton <akpm@linux-foundation.org>,
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	John Stultz <johnstul@linux.vnet.ibm.com>
References: <20090528164011.GA30104@linux-sh.org> <1243529547.28705.43.camel@desktop> <20090528165816.GA31688@linux-sh.org> <1243532324.28705.75.camel@desktop> <20090528175341.GA32118@linux-sh.org> <1243534252.28705.86.camel@desktop> <20090528182730.GA32767@linux-sh.org> <1243537463.28705.94.camel@desktop> <20090528193458.GA1122@linux-sh.org> <1243539663.28705.99.camel@desktop>
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On Thu, May 28, 2009 at 12:41:03PM -0700, Daniel Walker wrote:
> On Fri, 2009-05-29 at 04:34 +0900, Paul Mundt wrote:
> > > I'm still a little confused how kernel modules fit in here.. Are you
> > > saying a user would unload some certain driver which has a pin locked
> > > down and prevents the clocksource from working. Then the user would load
> > > the clocksource module which would now function, and that all would have
> > > to happen in order to enter a certain power state?
> > > 
> > Yes.
> 
> I'm assuming this isn't a low power state, this would be something more
> like suspend or hibernate right?
> 
Right, with the amount of hassle involved, it makes no sense for run-time
PM at least. So the suspend/hibernate use cases are mostly where it makes
sense.