From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760470Ab3LIEc7 (ORCPT ); Sun, 8 Dec 2013 23:32:59 -0500 Received: from mail-pd0-f172.google.com ([209.85.192.172]:43284 "EHLO mail-pd0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755614Ab3LIEcy (ORCPT ); Sun, 8 Dec 2013 23:32:54 -0500 Message-ID: <52A547F4.6080904@gmail.com> Date: Sun, 08 Dec 2013 21:32:52 -0700 From: David Ahern User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:24.0) Gecko/20100101 Thunderbird/24.1.1 MIME-Version: 1.0 To: Dongsheng Yang CC: Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org Subject: Re: [PATCH] perf tools: Fix bug for perf kvm report without guestmount. References: <1386365588-13046-1-git-send-email-yangds.fnst@cn.fujitsu.com> <20131206115627.GA2279@ghostprotocols.net> <52A5DFC9.6020105@cn.fujitsu.com> <52A53C3A.2090107@gmail.com> <52A5FA13.9000000@cn.fujitsu.com> In-Reply-To: <52A5FA13.9000000@cn.fujitsu.com> 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 12/9/13, 10:12 AM, Dongsheng Yang wrote: > On 12/08/2013 10:42 PM, David Ahern wrote: >> On 12/9/13, 8:20 AM, Dongsheng Yang wrote: >>> How about introduce an option named --guestpid? Then we can make the >>> usage of perf kvm >>> more clear: >>> * perf kvm --guestkallsyms --guestmodules --guestpid >>> [top|record|report] >>> This usage is for only one guest and will not resolve the >>> symbols from other guests. >> >> If there is only 1 guest then there should not be a problem right? You >> give perf a single guest kallsyms as the "default" and it works. >> --guestpid adds no value in that case. > > Yes, if there is only one guest is running, "default" guest is "the" > guest. Then with my patch in this thread applied, it works well. > > But consider this scenario, there are two guests are running, but we > need to record-report one of them. > > --guestmount can achieve this request, but as a shortcut of guestmount, > --guest{kallysms, modules} dose not > support it well, right? So, I think we can discard the default guest, > and use guestpid in record-report. No. Use cases: 1. one guest --guestkallsyms and --guestmodules apply to default guest; user should supply files that apply to the one guest. Supplying any other kallsyms is just nonsense. *NO* other arguments are needed. 2. more than 1 VM, *ALL* VMs running the same kernel --guestkallsyms and --guestmodules apply to default guest; user should supply files that apply to all of guests. No other arguments are needed. 3. more than 1 VM, VMs running different kernels. 1+ VMs running the same kernel --guestmount allows user to supply files that apply to all of guests based on pid. --guestkallsyms/guestmodules is used for any guest not showing up in guestmount. David