From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754555Ab0IFLfB (ORCPT ); Mon, 6 Sep 2010 07:35:01 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54314 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753568Ab0IFLfA (ORCPT ); Mon, 6 Sep 2010 07:35:00 -0400 Message-ID: <4C84D1CE.3070205@redhat.com> Date: Mon, 06 Sep 2010 14:34:38 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.8) Gecko/20100806 Fedora/3.1.2-1.fc13 Lightning/1.0b2pre Thunderbird/3.1.2 MIME-Version: 1.0 To: Peter Zijlstra CC: linux-perf-users@vger.kernel.org, linux-kernel , Ingo Molnar Subject: Re: disabling group leader perf_event References: <4C84B088.5050003@redhat.com> <1283772256.1930.303.camel@laptop> In-Reply-To: <1283772256.1930.303.camel@laptop> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/06/2010 02:24 PM, Peter Zijlstra wrote: > On Mon, 2010-09-06 at 12:12 +0300, Avi Kivity wrote: >> If I read the code correctly, disabling a group leader perf_event will >> disable the entire group. >> >> Is this correct? > Yeah, pretty much. Well, I never liked group_leader style APIs. I like different types for the container and the contained. But such is not unix. >> If so, how can I disable just the event itself? Can I allocate a dummy >> invent for the group leader so I can enable and disable each perf_event >> in the group individually? > Which makes me wonder why you use groups in the first place. Basically, to read() all events in one go. I have many of them. My current problem is that I have an event (kvm_exit) which I want to drill down by looking at a field (exit_reason). So I create lots of separate perf_events with a filter for each reason: kvm_exit(exit_reason==0), kvm_exit(exit_reason==1), etc. But filters are fairly slow (can have ~60 such events on AMD), so I want to make this drill-down optional. Current plan is to have a group for the basic events and another group for the drilldown events (each per-cpu), and activate the drilldown group on user request. perf will be able to schedule both groups concurrently since they only contain tracepoints, yes? -- error compiling committee.c: too many arguments to function