From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752870Ab2GONDi (ORCPT ); Sun, 15 Jul 2012 09:03:38 -0400 Received: from mx1.redhat.com ([209.132.183.28]:12838 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752708Ab2GONDb (ORCPT ); Sun, 15 Jul 2012 09:03:31 -0400 Message-ID: <5002BF9B.8090306@redhat.com> Date: Sun, 15 Jul 2012 16:03:23 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120605 Thunderbird/13.0 MIME-Version: 1.0 To: David Ahern CC: Gleb Natapov , Peter Zijlstra , LKML Subject: Re: perf with precise attribute kills all KVM based VMs References: <1341845396.3462.81.camel@twins> <4FFAEFF1.9000706@redhat.com> <1341845999.3462.86.camel@twins> <4FFCBD00.1030109@gmail.com> <20120711071006.GF23898@redhat.com> <1342000187.3462.134.camel@twins> <20120711095337.GJ23898@redhat.com> <4FFE4E8D.90606@gmail.com> <20120712042923.GG7298@redhat.com> <4FFEEB55.5070009@gmail.com> <20120712160634.GI7298@redhat.com> <50027A36.9070509@redhat.com> <5002BEE3.5060506@gmail.com> In-Reply-To: <5002BEE3.5060506@gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/15/2012 04:00 PM, David Ahern wrote: > On 7/15/12 2:07 AM, Avi Kivity wrote: >> On 07/12/2012 07:06 PM, Gleb Natapov wrote: >>>> >>>> Note the :pH this time. >>> I am not sure what perf kvm does with :pH modifier, but H modifier does >>> not make sense with perf kvm and should be reported as an error by >>> perf tool. >> >> Maybe it should refer to the guest vs. the nested guest... > > :H = host mode; you are thinking of :h for hypervisor mode. From > perf-list documentation: > > "Modifiers allow the user to restrict when events are > counted with 'u' for user-space, 'k' for kernel, 'h' for hypervisor. > Additional modifiers are 'G' for guest counting (in KVM guests) and 'H' > for host counting (not in KVM guests)." No, it's an additional distinction. A kvm guest can be in kernel mode, user mode, or in a nested guest mode (which has its own user mode and kernel mode). Currently we have no way of distinguishing between guest kernel mode and nested guest kernel mode. I assume 'h' means profiling the hypervisor from a guest (i.e. xen dom0)? -- error compiling committee.c: too many arguments to function