From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from 0122700014.0.fullrate.dk ([95.166.99.235]:35817 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756527Ab0CaRi6 (ORCPT ); Wed, 31 Mar 2010 13:38:58 -0400 Date: Wed, 31 Mar 2010 19:38:57 +0200 From: Jens Axboe Subject: Re: [PATCH] Do not delete cgroups upon completion of fio job Message-ID: <20100331173856.GD23510@kernel.dk> References: <20100331171931.GH14011@redhat.com> <20100331172600.GC23510@kernel.dk> <20100331173558.GI14011@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100331173558.GI14011@redhat.com> Sender: fio-owner@vger.kernel.org List-Id: fio@vger.kernel.org To: Vivek Goyal Cc: fio@vger.kernel.org On Wed, Mar 31 2010, Vivek Goyal wrote: > On Wed, Mar 31, 2010 at 07:26:00PM +0200, Jens Axboe wrote: > > On Wed, Mar 31 2010, Vivek Goyal wrote: > > > Currently upon fio job completion, we delete the cgroups. But in the > > > process we also loose important debugging information presetn in cgroup > > > files. For example time information in blkio.time, sector information in > > > blkio.sectors and how many a times a group was dequeued blkio.dequeue. > > > Leaving the cgroups as it is, allows one to go and inspect those files > > > after the fio job is complete. > > > > > > Secondly, cgroups might have already been created by user before fio job > > > started. In that case it is not very right to delete cgroups after job > > > completion. > > > > Confused, I was pretty sure that I added code back then to only delete > > cgroups when they were created by fio. Checking, that is what it should > > do - we only add the cgroup to the kill list, if we were the one to > > create it. That was on purpose, since I did not want to leave them > > around. > > Sorry, I did not check properly. Upon retest, I see cgroups are not being > deleted if these were not created by fio. > > > > > I'd suggest adding a specific option to NOT kill a cgroup. Or you could > > have a post_exec option that tar's up the contents of that directory, > > perhaps even formalized? > > I think adding an option to not kill a cgroup looks good to me as I don't > have to do some more scripting to tar and then untar and read cgroup debug > files. > > I will send a patch for that option. Agree, it's probably best. Plus it sort-of matches the unlink option applied to files created. So I'd gladly take that. -- Jens Axboe