From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olivier Hanesse Subject: Re: Xen 4 TSC problems Date: Thu, 24 Feb 2011 15:20:01 +0100 Message-ID: References: <4D6648220200007800033769@vpn.id2.novell.com>

<4D665F3102000078000337B6@vpn.id2.novell.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1821090853==" Return-path: In-Reply-To: <4D665F3102000078000337B6@vpn.id2.novell.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Jan Beulich Cc: Jeremy Fitzhardinge , xen-devel@lists.xensource.com, Keir Fraser , Dan Magenheimer , Xen Users , Mark Adams List-Id: xen-devel@lists.xenproject.org --===============1821090853== Content-Type: multipart/alternative; boundary=0016367f985ebb86cd049d07e863 --0016367f985ebb86cd049d07e863 Content-Type: text/plain; charset=ISO-8859-1 Both dom0 and domUs are affected by this" jump". I expect to see something like "TSC marked as reliable, warp = 0". I got this on newer hardware with same config/distros. Is there a way to measure if it is a TSC warp ? to point out a cpu tsc issue ? 2011/2/24 Jan Beulich > >>> On 24.02.11 at 12:57, Olivier Hanesse > wrote: > > I tried to turn off cstates with max_cstate=0 without success (still "not > > reliable"). > > > > With cpuidle=0, I also got : > > > > (XEN) TSC has constant rate, deep Cstates possible, so not reliable, > > warp=3022 (count=1) > > This message by itself isn't telling much I believe. > > > xm info | grep command > > xen_commandline : dom0_mem=512M cpuidle=0 loglvl=all > guest_loglvl=all > > dom0_max_vcpus=1 dom0_vcpus_pin console=vga,com1 com1=19200,8n1 > > > > Keir : > > > > Using clocksource=pit : > > > > (XEN) Platform timer is 1.193MHz PIT > > > > I also got : > > > > (XEN) TSC has constant rate, deep Cstates possible, so not reliable, > > warp=3262 (count=2) > > The question is whether any of this eliminates the time jumps seen > by your DomU-s (from your past mails I wasn't actually sure whether > Dom0 also experienced this problem, albeit it would be odd if it didn't). > > Jan > > Jan > > --0016367f985ebb86cd049d07e863 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Both dom0 and domUs are affected by this" jump".

I e= xpect to see something like "TSC marked as reliable, warp =3D 0".= =A0

I got this on newer hardware with same config/distros.

<= div>

Is there a way to measure if it is a TSC warp ? to point out= a cpu tsc issue ?

2011/2/24 Jan Beulich <JBeulich@novell.com>

>>> On 24.02.11 = at 12:57, Olivier Hanesse <= olivier.hanesse@gmail.com> wrote:
> I tried to turn off cstates with max_cstate=3D0 without success (still= "not
> reliable").
>
> With cpuidle=3D0, I also got :
>
> (XEN) TSC has constant rate, deep Cstates possible, so not reliable, > warp=3D3022 (count=3D1)

This message by itself isn't telling much I believe.

> xm info | grep command
> xen_commandline =A0 =A0 =A0 =A0: dom0_mem=3D512M cpuidle=3D0 loglvl=3D= all guest_loglvl=3Dall
> dom0_max_vcpus=3D1 dom0_vcpus_pin console=3Dvga,com1 com1=3D19200,8n1<= br> >
> Keir :
>
> Using clocksource=3Dpit :
>
> (XEN) Platform timer is 1.193MHz PIT
>
> I also got :
>
> (XEN) TSC has constant rate, deep Cstates possible, so not reliable, > warp=3D3262 (count=3D2)

The question is whether any of this eliminates the time jumps seen by your DomU-s (from your past mails I wasn't actually sure whether
Dom0 also experienced this problem, albeit it would be odd if it didn't= ).

Jan

Jan

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