Re: [Fedora-xen] [Xen-devel] 4.1.2 very slow without upstream patches, but fast with them, also 4.2 very slow

[Konrad Rzeszutek Wilk]

On Mon, Aug 06, 2012 at 01:41:07PM +0100, Malcolm Crossley wrote:
> On 06/08/12 11:12, Peter Maloney wrote:
> > my AMD FX-8150 system with vanilla source code is super slow, both the
> > dom0 and domUs. However, after I merge the upstream patches I found in
> > the openSUSE rpm, it runs normally.
> >
> > I tried 4.2-unstable and it was the same. There was no rc1 when I tested
> > it about 1.5 weeks ago. And 4.2 has the same horrible performance, and
> > obviously those patches won't work any more since the 4.2 code looks
> > completely reorganized, so I'm stuck with 4.1.2
> >
> > Here is the rpm I was using at the time:
> > http://download.opensuse.org/update/12.1/src/xen-4.1.2_16-1.7.1.src.rpm
> >
> > To see the list of the patches and what order to apply them, see the
> > spec file.
> >
> > Please make sure this performance issue is fixed for the 4.2 release.
> > And I would be happy to test whatever files you send me.
> >
> > Xen-devel mailing list
> > [e-mail]
> > http://lists.xen.org/xen-devel
>
> I suspect you may need the following patch to improve your 4.1.2
> performance:
>
> http://xenbits.xen.org/hg/xen-4.1-testing.hg/rev/435493696053
>
> The cache flush on every C2 transition is very expensive and causes
> a large slow down.
>
> 4.1.3-rc3 already includes that patch so it would be worth testing
> that version.

MA Young, could this be back-ported in the F17 and F16. I belive
Micahel Petullo setup a bug for that?
> Malcolm
>
> Xen-devel mailing list
> [e-mail]
> http://lists.xen.org/xen-devel

[Xen-devel] 4.1.2 very slow without upstream patches, but fast with them, also 4.2 very slow

[M A Young]

On Mon, 6 Aug 2012, Konrad Rzeszutek Wilk wrote:
> On Mon, Aug 06, 2012 at 01:41:07PM +0100, Malcolm Crossley wrote:
> > I suspect you may need the following patch to improve your 4.1.2
> > performance:
> >
> > http://xenbits.xen.org/hg/xen-4.1-testing.hg/rev/435493696053
> >
> > The cache flush on every C2 transition is very expensive and causes
> > a large slow down.
> >
> > 4.1.3-rc3 already includes that patch so it would be worth testing
> > that version.
>
> MA Young, could this be back-ported in the F17 and F16. I belive
> Micahel Petullo setup a bug for that?

I don't recall I seeing a bug for this but the patch is in 
xen-4.1.2-25.fc18 and xen-4.1.2-25.fc17 (which is building now).

Michael Young

[Xen-devel] 4.1.2 very slow without upstream patches, but fast with them, also 4.2 very slow

[W. Michael Petullo]

> > > I suspect you may need the following patch to improve your 4.1.2
> > > performance:
> > >
> > > http://xenbits.xen.org/hg/xen-4.1-testing.hg/rev/435493696053
> > >
> > > The cache flush on every C2 transition is very expensive and causes
> > > a large slow down.
> > > 4.1.3-rc3 already includes that patch so it would be worth testing
> > > that version.
> > MA Young, could this be back-ported in the F17 and F16. I belive
> > Micahel Petullo setup a bug for that?
> I don't recall I seeing a bug for this but the patch is in
> xen-4.1.2-25.fc18 and xen-4.1.2-25.fc17 (which is building now).

The performance-related bug I filed is at:

https://bugzilla.redhat.com/show_bug.cgi?id=841330