[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Xen-devel] Virtualization of the CPU Performance Monitoring Unit
- To: xen-devel@xxxxxxxxxxxxx
- From: Dietmar Hahn <dietmar.hahn@xxxxxxxxxxxxxx>
- Date: Tue, 17 Apr 2012 08:11:19 +0200
- Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>, Lin Ming <mlin@xxxxxxxxxxxxx>, wei.huang2@xxxxxxx, marcus.granado@xxxxxxxxxx, wei.wang2@xxxxxxx, Konrad Rzeszutek Wilk <konrad@xxxxxxxxxx>
- Delivery-date: Tue, 17 Apr 2012 06:11:57 +0000
- Dkim-signature: v=1; a=rsa-sha256; c=simple/simple; d=ts.fujitsu.com; i=dietmar.hahn@xxxxxxxxxxxxxx; q=dns/txt; s=s1536b; t=1334643081; x=1366179081; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=E490qf13uzPaO9uroh5Oe5F4cCJ8co7k7iSYlxLC5zM=; b=pV5dRyy5cvpJYEqJfyKorpivNkyrBNO5k9CacFCIgGHM0U2rHqBYuWUP yFnMt6UBzq3vo9qr7hEDYmOMHVFJb0Cawd+J3/TKUC8I4Ks9IfYkaQJG/ mYb6bZS6QNTA06CUCp86MRZF0RqHOMcNsMMYC714qp+ByI6kxSwnzXfg9 eqWm4hQcNoe/980djRQiEK0Stw8R8LZ/EH2nW1z+R1dDB9M4/J19RU//Q hgqdk/sujKA+wxcbgP+PiNC7CZpLQ;
- Domainkey-signature: s=s1536a; d=ts.fujitsu.com; c=nofws; q=dns; h=X-SBRSScore:X-IronPort-AV:Received:X-IronPort-AV: Received:Received:From:To:Cc:Subject:Date:Message-ID: User-Agent:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding:Content-Type; b=i1yxoluJKSSP+E70rNtzowLL2/BCEaemCQYhtltbSyyl+tHSnrYLQBNh kMqoQA0Q2d7WbXq+ACbOxM1515zzLJQpC5witTWiL+xlPvFJNdHPfwr4V XPmrrJAfPR+u4J2btxk0Q16OmBK4siBtxcb4oqgC8cgRD09leXK7SPMLG P9VkZC+03ulCSiwo3G57lmZKFy15yM/RnxMgO/+F91ElnNIvP/1im6eu+ SG7bv8Le4m7Q/3kYUl1rVwgdS/kwg;
- List-id: Xen developer discussion <xen-devel.lists.xen.org>
Am Montag 16 April 2012, 13:39:36 schrieb Konrad Rzeszutek Wilk:
> On Mon, Apr 16, 2012 at 04:16:07PM +0800, Lin Ming wrote:
> > On Wed, Apr 11, 2012 at 10:30 PM, Lin Ming <mlin@xxxxxxxxxxxxx> wrote:
> >
> > [....]
> >
> > >> That isn't actually true. If you run it, you will see it working
> > >> in the guest - it just that it does not use the performence counters
> > >> but instead uses the timer to sample data.
> > >
> > > Right, I mean "hardware event" does not work.
> > >
> > > Hardware event, for example, perf top -e cycles, does not work.
> >
> > Just found that vpmu is disabled by default.
> > You need to pass xen boot parameter "vpmu" to make hardware event work.
>
> Oh, I wonder why it was disabled by default? Wei, would you know
> by any chance?
This had to do with a problem in the intel nehalem processors which could cause
endless interrupt loops in the hypervisor if a hvm guest uses the performance
counters so Keir proposed to add the vpmu boot flag.
http://lists.xen.org/archives/html/xen-devel/2009-10/msg01460.html
and
http://lists.xen.org/archives/html/xen-devel/2009-11/msg00088.html
Dietmar
>
> >
> > > Software event, for example, perf top -e cpu-clock, works.
> >
> > So both hardware and software event work in DomU.
> > Great!
>
> Excellent!
> >
> > >
> > >>
> > >> > Run "perf top", but no data was collected.
> > >>
> > >> Hm, I am able to collect data using Fedora Core 16 PV guest.
> > >> For dom0 or domU? For dom0 there is a bug somewhere where
> > >
> > > For domU HVM guest.
> > > I have problem to run domU PV guest. Still looking at it.
> > >
> > >> the machine crashes after 30 seconds or so - hadn't actually
> > >> gotten to the bottom of it. There was an email thread:
> > >> https://lkml.org/lkml/2012/2/12/74 about this.
> > >>
> > >> Patches are most welcome!
> >
> > Here are the patches.
> > https://lkml.org/lkml/2012/4/15/12
>
> Let me play with them a bit. At first glance they look ok - but I recall
> Peter Z saying something about not implementing the IRQ WORKER, but I can't
> recall the reasons.
> >
> > Regards,
> > Lin Ming
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel
>
--
Company details: http://ts.fujitsu.com/imprint.html
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel