From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: Virtualization of the CPU Performance Monitoring Unit Date: Mon, 16 Apr 2012 13:39:36 -0400 Message-ID: <20120416173936.GD18314@phenom.dumpdata.com> References: <4F7F1D14.9040208@amd.com> <20120411134648.GB21703@andromeda.dapyr.net> <1334154629.3943.4.camel@hp6530s> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Lin Ming , wei.wang2@amd.com Cc: Konrad Rzeszutek Wilk , wei.huang2@amd.com, marcus.granado@citrix.com, xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org On Mon, Apr 16, 2012 at 04:16:07PM +0800, Lin Ming wrote: > On Wed, Apr 11, 2012 at 10:30 PM, Lin Ming 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? > > > 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