Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1329085

Re: [PATCH v1] clocksource: atmel-pit: register as a sched_clock

From Boris Brezillon <boris.brezillon@free-electrons.com>
Newsgroups linux.kernel
Subject Re: [PATCH v1] clocksource: atmel-pit: register as a sched_clock
Date 2016-02-08 15:10 +0100
Message-ID <qZUFR-6nz-29@gated-at.bofh.it> (permalink)
References <qYvTd-53o-27@gated-at.bofh.it> <qZUcP-5U1-37@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


+ Alexandre

Hi Daniel,

On Mon, 8 Feb 2016 14:33:04 +0100
Daniel Lezcano <daniel.lezcano@linaro.org> wrote:

> On 02/04/2016 06:21 PM, Romain Izard wrote:
> > Register the counter of the Periodic Interval Timer as a possible source
> > for sched_clock. This provides a better precision than the jiffies-based
> > default.
> >
> > Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
> 
> Nicolas, Boris,
> 
> Are you ok with this patch ?

Not sure yet :). On most platforms we are also declaring a clocksource
based on the TCB IP, and this one provides a better precision than the
PIT clocksource.
What happens if the PIT is de-activated while it's still supposed to
provide the sched_clock(). Is there a way to flag the clocksource as
still needed so that the core does not shut it down by when the TCB
clocksource comes in.

Best Regards,

Boris

-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com

Back to linux.kernel | Previous | NextPrevious in thread | Find similar | Unroll thread


Thread

[PATCH v1] clocksource: atmel-pit: register as a sched_clock Romain Izard <romain.izard.pro@gmail.com> - 2016-02-04 18:30 +0100
  Re: [PATCH v1] clocksource: atmel-pit: register as a sched_clock Daniel Lezcano <daniel.lezcano@linaro.org> - 2016-02-08 14:40 +0100
    Re: [PATCH v1] clocksource: atmel-pit: register as a sched_clock Boris Brezillon <boris.brezillon@free-electrons.com> - 2016-02-08 15:10 +0100

csiph-web