Re: [PATCH v2] clocksource: atmel-pit: register as a sched_clock

From	Sylvain Rochet <sylvain.rochet@finsecur.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2] clocksource: atmel-pit: register as a sched_clock
Date	2016-02-24 17:50 +0100
Message-ID	<r5KNt-7fP-33@gated-at.bofh.it> (permalink)
References	<r5KaJ-6ZF-9@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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Hi,

On Wed, Feb 24, 2016 at 05:04:42PM +0100, Romain Izard wrote:
> Register the counter of the Periodic Interval Timer as a possible source
> for sched_clock. Keep the timer running even if the related clockevent
> is disabled.
> 
> This provides a better precision than the jiffies-based default. The
> TCB clocksource does not work, as it is registered too late in the
> initialization sequence.

I have mixed feelings about that, but this is probably just a 
misunderstanding from my part.

The PIT timer should not be used for systems with PM_SUSPEND enabled and 
used because it takes ages to synchronize on resume, how does this patch 
affect that ?

Ref: commit ac34ad27fc ("clockevents: Do not suspend/resume if unused")

Sylvain

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[PATCH v2] clocksource: atmel-pit: register as a sched_clock Romain Izard <romain.izard.pro@gmail.com> - 2016-02-24 17:10 +0100
  Re: [PATCH v2] clocksource: atmel-pit: register as a sched_clock Alexandre Belloni <alexandre.belloni@free-electrons.com> - 2016-02-24 17:20 +0100
  Re: [PATCH v2] clocksource: atmel-pit: register as a sched_clock Romain Izard <romain.izard.pro@gmail.com> - 2016-02-24 17:50 +0100
    Re: [PATCH v2] clocksource: atmel-pit: register as a sched_clock Nicolas Ferre <nicolas.ferre@atmel.com> - 2016-02-24 18:20 +0100
  Re: [PATCH v2] clocksource: atmel-pit: register as a sched_clock Sylvain Rochet <sylvain.rochet@finsecur.com> - 2016-02-24 17:50 +0100

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