Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751316AbaLPR3h (ORCPT ); Tue, 16 Dec 2014 12:29:37 -0500 Received: from mail-ob0-f174.google.com ([209.85.214.174]:41071 "EHLO mail-ob0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751083AbaLPR3g (ORCPT ); Tue, 16 Dec 2014 12:29:36 -0500 MIME-Version: 1.0 In-Reply-To: References: <20141215220150.GP9845@kernel.org> Date: Tue, 16 Dec 2014 12:29:35 -0500 Message-ID: Subject: Re: [perf tool] cgroup support broken on Debian? From: Stephane Eranian To: Vince Weaver Cc: Stephane Eranian , Arnaldo Carvalho de Melo , LKML , Ingo Molnar , Peter Zijlstra , Tejun Heo , Li Zefan Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Vince, On Tue, Dec 16, 2014 at 12:17 PM, Vince Weaver wrote: > On Mon, 15 Dec 2014, Stephane Eranian wrote: >> On Mon, Dec 15, 2014 at 11:01 PM, Arnaldo Carvalho de Melo wrote: > >> fs is visible. The cgroup file system type is not there anymore. They are using >> tmpfs which is not ideal to detect just cgroup. Looks like now, we have to look >> at the mount point which is flaky. > > The trivial fix is to just always assume things will be under > /sys/fs/cgroup > which looks like to be the new official mount point. > > This will break on older systems though, or systems that mount cgroupfs in > multiple locations. > > Another alternative is to change the interface to require the full > cgroupfs pathname as an argument to -G > That's not user friendly! We need to detect where this is mounted to. I think we can try the tmpfs mount points. Just need to then check if a file entry that can only exist for cgroups is there, such as cgroups.procs. >> Yes, the error needs to be improved or even added. The following common >> errors are encountered: >> >> - -G option requires -a (system-wide), otherwise it does not work at all >> - -G option must always be specified AFTER the ALL event list >> - -G and explicit event groups is not well supported by the tool yet. >> An event group must have the same cgroup. >> - Cgroups are specified per event >> - -G cgroup order follows the event order: -e e1, e2, e3 -G g1,g2,g3: >> g1->e1, g2->e2, g3->e3 >> - It is possible to indicate no cgroup with -G: -e e1,e2,e3 -G g1,,g3 >> using empty group (,,) > > I'll see if I can get a patch together that impements this. > > Vince -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/