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Date: Wed, 8 Dec 2010 16:43:33 +0100
Message-ID: <AANLkTi=TYecfTGZ8iUDJPy+2HFTFYOjDEVxxE_1_Dvwf@mail.gmail.com>
Subject: Re: [BUG] 2.6.37-rc3 massive interactivity regression on ARM
From: Linus Walleij <linus.ml.walleij@gmail.com>
To: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>,
        Mikael Pettersson <mikpe@it.uu.se>,
        Venkatesh Pallipadi <venki@google.com>, Ingo Molnar <mingo@elte.hu>,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        John Stultz <johnstul@us.ibm.com>
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2010/12/8 Peter Zijlstra <a.p.zijlstra@chello.nl>:

> Like said, John Stultz was already looking at doing something like that
> because there's a number of architectures suffering this same problem
> and they're all already using part of the clocksource infrastructure to
> implement the sched_clock() interface simply because they only have a
> single hardware resource.

I was in on that discussion and for the Ux500 this patch was the
outcome:
http://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=6488/1

It seems to work, mostly, it's based off Nico's orion code and
just tries to make everything as explicit as possible.

Uwe has also been onto it I think.

Yours,
Linus Walleij
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