From: Ingo Molnar <mingo@elte.hu>
To: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Zachary Amsden <zach@vmware.com>,
Glauber de Oliveira Costa <gcosta@redhat.com>,
linux-kernel@vger.kernel.org, tglx@linutronix.de,
rusty@rustcorp.com.au, --cc@redhat.com, avi@quramnet.com,
kvm-devel@lists.sourceforge.net,
Glauber de Oliveira Costa <glauber@t60.localdomain>,
Dan Hecht <dhecht@vmware.com>, Garrett Smith <garrett@vmware.com>
Subject: Re: [PATCH] raise tsc clocksource rating
Date: Mon, 29 Oct 2007 23:55:28 +0100 [thread overview]
Message-ID: <20071029225528.GA31293@elte.hu> (raw)
In-Reply-To: <47266431.1010500@goop.org>
* Jeremy Fitzhardinge <jeremy@goop.org> wrote:
> > if it's inaccurate why are you exposing it to the guest then? Native
> > only uses the TSC if it's safe and accurate to do so.
>
> It is used as part of the Xen clocksource as a short term
> extrapolator, with correction parameters supplied by the hypervisor.
> It should never be used directly.
that's totally broken then. You cannot create an SMP-safe monotonic
clocksource via interpolation - native does not do it either. Good thing
this problem got exposed, it needs to be fixed.
Ingo
next prev parent reply other threads:[~2007-10-29 22:55 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-29 23:10 [PATCH] raise tsc clocksource rating Glauber de Oliveira Costa
2007-10-29 23:10 ` Glauber de Oliveira Costa
2007-10-29 22:17 ` Thomas Gleixner
2007-10-29 22:17 ` Thomas Gleixner
2007-10-29 22:36 ` Ingo Molnar
2007-10-30 1:26 ` john stultz
2007-10-30 2:39 ` Rusty Russell
2007-10-30 2:39 ` Rusty Russell
2007-10-30 7:37 ` Ingo Molnar
2007-10-30 7:37 ` Ingo Molnar
2007-10-30 10:52 ` Rusty Russell
2007-10-30 10:52 ` Rusty Russell
2007-10-30 12:13 ` Glauber de Oliveira Costa
2007-10-30 12:13 ` Glauber de Oliveira Costa
2007-10-29 22:42 ` Zachary Amsden
2007-10-29 22:42 ` Zachary Amsden
2007-10-29 22:45 ` Jeremy Fitzhardinge
2007-10-29 22:45 ` Jeremy Fitzhardinge
2007-10-29 22:48 ` Ingo Molnar
2007-10-29 22:52 ` Jeremy Fitzhardinge
2007-10-29 22:52 ` Jeremy Fitzhardinge
2007-10-29 22:55 ` Ingo Molnar [this message]
2007-10-29 23:17 ` Jeremy Fitzhardinge
2007-10-29 23:17 ` Jeremy Fitzhardinge
2007-10-29 23:21 ` Ingo Molnar
2007-10-29 23:21 ` Ingo Molnar
2007-10-29 23:33 ` Jeremy Fitzhardinge
2007-10-29 23:33 ` Jeremy Fitzhardinge
2007-10-30 0:45 ` Ian Pratt
2007-10-30 0:45 ` Ian Pratt
2007-10-30 7:19 ` Ingo Molnar
2007-10-30 7:19 ` Ingo Molnar
2007-10-29 22:55 ` Zachary Amsden
2007-10-29 22:55 ` Zachary Amsden
2007-10-29 23:02 ` Ingo Molnar
2007-10-29 23:13 ` Zachary Amsden
2007-10-29 23:17 ` Ingo Molnar
2007-10-29 23:17 ` Ingo Molnar
2007-10-30 12:02 ` Glauber de Oliveira Costa
2007-10-30 12:02 ` Glauber de Oliveira Costa
2007-10-30 17:58 ` Zachary Amsden
2007-10-30 17:58 ` Zachary Amsden
2007-10-29 23:24 ` Dan Hecht
2007-10-29 23:24 ` Dan Hecht
2007-10-30 4:24 ` [kvm-devel] " Avi Kivity
2007-10-30 4:24 ` Avi Kivity
2007-10-30 7:14 ` Ingo Molnar
2007-10-30 7:14 ` Ingo Molnar
2007-10-30 11:59 ` Glauber de Oliveira Costa
2007-10-30 11:59 ` Glauber de Oliveira Costa
2007-10-30 0:17 ` H. Peter Anvin
2007-10-30 0:17 ` H. Peter Anvin
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