From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755201Ab2GJXip (ORCPT ); Tue, 10 Jul 2012 19:38:45 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:38581 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755038Ab2GJXin (ORCPT ); Tue, 10 Jul 2012 19:38:43 -0400 Message-ID: <4FFCBD00.1030109@gmail.com> Date: Tue, 10 Jul 2012 17:38:40 -0600 From: David Ahern User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Peter Zijlstra CC: Avi Kivity , Gleb Natapov , LKML Subject: Re: perf with precise attribute kills all KVM based VMs References: <4FFAE6D8.5050609@gmail.com> <20120709141904.GC7298@redhat.com> <1341843844.3462.75.camel@twins> <4FFAED16.7050204@redhat.com> <4FFAEF13.7010108@gmail.com> <1341845396.3462.81.camel@twins> <4FFAEFF1.9000706@redhat.com> <1341845999.3462.86.camel@twins> In-Reply-To: <1341845999.3462.86.camel@twins> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/9/12 8:59 AM, Peter Zijlstra wrote: > On Mon, 2012-07-09 at 17:51 +0300, Avi Kivity wrote: >> On 07/09/2012 05:49 PM, Peter Zijlstra wrote: >>> On Mon, 2012-07-09 at 08:47 -0600, David Ahern wrote: >>>> >>>> I found this testing changes to perf-kvm, but found the problem extends >>>> to just perf-record. With perf-record exclude_guest defaults to 1. See >>>> tools/perf/util/util.c, event_attr_init(). >>> >>> You lost me there.. so perf-record defaults to exclude_guest=1 (which >>> would make the proposed patch I just send actually possible), but its >>> still going *bang* ? >> >> It's possible that the DS writes overshoot the MSR... or that there's a >> bug somewhere. > > OK, so the first thing to stare at is in what order the MSRs are > touched, I think you first need to stop the counter, then clear the PEBS > bits, then clear the DS_AREA one. > Any updates on the options for this or is there still squinting going on with MSR orders? I guess it's a good thing Ingo's request for :pp to be the default was not implemented: https://lkml.org/lkml/2012/5/14/26 David