From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933055AbcGLLrn (ORCPT ); Tue, 12 Jul 2016 07:47:43 -0400 Received: from merlin.infradead.org ([205.233.59.134]:41085 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751187AbcGLLrm (ORCPT ); Tue, 12 Jul 2016 07:47:42 -0400 Date: Tue, 12 Jul 2016 13:47:34 +0200 From: Peter Zijlstra To: Aravinda Prasad Cc: linux-kernel@vger.kernel.org, rostedt@goodmis.org, mingo@redhat.com, paulus@samba.org, acme@kernel.org, ebiederm@xmission.com, hbathini@linux.vnet.ibm.com, ananth@in.ibm.com Subject: Re: [RFC PATCH 2/2] perf: Filter events based on perf-namespace Message-ID: <20160712114734.GL30154@twins.programming.kicks-ass.net> References: <20160614164530.4192.79560.stgit@aravindap> <20160614164951.4192.66724.stgit@aravindap> <20160627155002.GD30909@twins.programming.kicks-ass.net> <5784B7B9.5020901@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5784B7B9.5020901@linux.vnet.ibm.com> User-Agent: Mutt/1.5.23.1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 12, 2016 at 02:56:17PM +0530, Aravinda Prasad wrote: > > > On Monday 27 June 2016 09:20 PM, Peter Zijlstra wrote: > > On Tue, Jun 14, 2016 at 10:19:51PM +0530, Aravinda Prasad wrote: > >> Whenever perf tool is executed inside a container, this > >> patch restricts the events to the perf-namespace in which > >> the perf tool is executing. > >> > >> This patch is based on the existing support available > >> for tracing with cgroups. > >> > >> TODO: > >> - Avoid code duplication. > > > > Can't you, at perf_event_open() time, convert a per-cpu event into a > > per-cpu-per-cgroup event for these namespace thingies? > > > > That seems to immediately and completely remove all that duplication. > > Sorry for the delay in the response. > > I was looking into a way how a per-cpu event can be converted to > per-cpu-per-cgroup event at perf_event_open() but could not figure out > how to do this conversion. The cgroup event expects the fd of the cgroup > directory in cgroupfs and in this case we don't have any fd passed in. > Not sure if I am missing anything. Would not the current namespace have a link to the correct cgroup? Wasn't that the entire point of the namespace thing?