From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: Questing regarding KVM Guest PMU Date: Sun, 18 Mar 2012 18:51:20 +0200 Message-ID: <20120318165120.GF27306@redhat.com> References: <20120318103020.GA27306@redhat.com> <20120318145045.GD27306@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org To: shashank rachamalla Return-path: Received: from mx1.redhat.com ([209.132.183.28]:52898 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755906Ab2CRQvX (ORCPT ); Sun, 18 Mar 2012 12:51:23 -0400 Content-Disposition: inline In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On Sun, Mar 18, 2012 at 09:47:55PM +0530, shashank rachamalla wrote: > >> I guess things are working fine with perf. But why not with oprofile ? > >> > > Looks like it. I never tried oprofile. Will try to reproduce your > > problem and see what oprofile is doing. > > I am using ubuntu 10.04 with 2.6.32-21-generic kernel as guest and > oprofile 0.9.6. > Also, I have tried to capture kvm-events ( perf patch ) in host while > running oprofile and perf in guest. > Please see the attachment. I have run the tests in three cases for the > around 5 secs. > > There are more number of MSR reads and writes in case of perf which I > think is normal. However, there are very few MSR reads and writes with > oprofile. Also, the number of NMI exceptions are too high in case of > oprofile. > Which host kernel are you using? Try latest kvm.git and check if you see something unusual in dmesg. -- Gleb.