This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


RE: [Xen-devel] XEN 4.1 pci passthru performance regression?

On Wed, 2011-06-01 at 08:55 +0100, Ian Campbell wrote:
> On Wed, 2011-06-01 at 02:41 +0100, Cao, Buddy wrote:
> > Thanks Ian for you reply.
> >
> > >Are you referring only to control operation performance or also to
> > >actual guest performance?
> >
> > It does not impact actual guest performance, only make vm start and 
> > shutdown slow.
> Oh good!
> > >Do you find that guests without any PCI passthrough have also slowed
> > >down or is the issue purely for guests with a passed-through device?
> >
> > The guests without any PCI passthrough works as well as xen4.0.2.
> Also good.
> > I tired xl, but looks it always returns "libxl....." relevant error,
> > and none of the command can run properly
> Well, we should also try and resolve this -- xl is expected to work in
> 4.1. Did you see: http://wiki.xen.org/xenwiki/MigrationGuideToXen4.1+ ?
> Please tell us the specifics of the xl failure.
> I tried starting a PV guest with a passed through device with both xm
> and xl and there was no obvious delay on startup or shutdown.
> Unfortunately I don't have a test box which can do passthrough to HVM
> guests at the moment (I'll see if I can scare one up). In the meantime
> perhaps you could add some extra logging to xend to see where the time
> is spent and/or report the xl failues as requested above.
> Also, please can you try xen-unstable.hg to see if the problem still
> exists there.

I found a suitable box and tested xen-unstable.hg.

xm does seem to suffer from a delay of some sort on startup, but xl
doesn't seem to.

I'm afraid I don't have time to dig into xend any further myself.


Xen-devel mailing list

<Prev in Thread] Current Thread [Next in Thread>