From: Andreas Kleen <ak@suse.de>
To: Daniel Walker <dwalker@mvista.com>
Cc: Guillaume Chazarain <guichaz@gmail.com>,
john stultz <johnstul@us.ibm.com>,
mathieu.desnoyers@polymtl.ca, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Add an offset in the cyc2ns computation to fix sched_clock jumps
Date: Fri, 16 Mar 2007 19:36:18 +0100 (CET) [thread overview]
Message-ID: <5920992.1174070178992.SLOX.WebMail.wwwrun@imap-dhs.suse.de> (raw)
In-Reply-To: <1174069846.3101.113.camel@imap.mvista.com>
Am Fr 16.03.2007 19:30 schrieb Daniel Walker <dwalker@mvista.com>:
> On Fri, 2007-03-16 at 19:14 +0100, Guillaume Chazarain wrote:
> > Hello,
> >
> > The scheduling problems I reported in the thread:
> > http://lkml.org/lkml/2007/3/3/128
> > are caused by the set_cyc2ns_scale() function called when the CPU
> > speed changes.
> > Changing the scale causes a warp in the value returned by
> > sched_clock().
> >
>
> Did you explain what the "werirdnes" was exactly? If not, could you?
I fixed this in my own version of the change by marking it unstable
during the transition
(concept stolen from Jiri's patch). Basically watch the notifiers for
before/after
and while the transition is in progress always ask for that underlying
monotonic ktime.
-Andi
next prev parent reply other threads:[~2007-03-16 18:36 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-16 18:14 Guillaume Chazarain
2007-03-16 18:22 ` Andi Kleen
2007-03-16 18:48 ` Guillaume Chazarain
2007-03-16 18:26 ` john stultz
2007-03-16 18:30 ` Daniel Walker
2007-03-16 18:36 ` Andreas Kleen [this message]
2007-03-16 18:44 ` Guillaume Chazarain
2007-03-18 21:08 ` Mathieu Desnoyers
2007-03-18 22:09 ` Guillaume Chazarain
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