From mboxrd@z Thu Jan 1 00:00:00 1970 From: Glauber Costa Subject: Re: [PATCH v3 04/13] kmem accounting basic infrastructure Date: Thu, 27 Sep 2012 16:40:03 +0400 Message-ID: <50644923.2060008@parallels.com> References: <50637298.2090904@parallels.com> <20120926221046.GA10453@mtj.dyndns.org> <506381B2.2060806@parallels.com> <20120926224235.GB10453@mtj.dyndns.org> <50638793.7060806@parallels.com> <20120926230807.GC10453@mtj.dyndns.org> <50638DBB.4000002@parallels.com> <20120926233334.GD10453@mtj.dyndns.org> <20120927121558.GB29104@dhcp22.suse.cz> <506444A7.5060303@parallels.com> <20120927124031.GC29104@dhcp22.suse.cz> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20120927124031.GC29104-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org> Sender: cgroups-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Michal Hocko Cc: Tejun Heo , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kamezawa.hiroyu-+CUm20s59erQFUHtdCDX3A@public.gmane.org, devel-GEFAQzZX7r8dnm+yROfE0A@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Suleiman Souhlal , Frederic Weisbecker , Mel Gorman , David Rientjes , Johannes Weiner On 09/27/2012 04:40 PM, Michal Hocko wrote: > On Thu 27-09-12 16:20:55, Glauber Costa wrote: >> On 09/27/2012 04:15 PM, Michal Hocko wrote: >>> On Wed 26-09-12 16:33:34, Tejun Heo wrote: >>> [...] >>>>>> So, this seems properly crazy to me at the similar level of >>>>>> use_hierarchy fiasco. I'm gonna NACK on this. >>>>> >>>>> As I said: all use cases I particularly care about are covered by a >>>>> global switch. >>>>> >>>>> I am laying down my views because I really believe they make more sense. >>>>> But at some point, of course, I'll shut up if I believe I am a lone voice. >>>>> >>>>> I believe it should still be good to hear from mhocko and kame, but from >>>>> your point of view, would all the rest, plus the introduction of a >>>>> global switch make it acceptable to you? >>>> >>>> The only thing I'm whining about is per-node switch + silently >>>> ignoring past accounting, so if those two are solved, I think I'm >>>> pretty happy with the rest. >>> >>> I think that per-group "switch" is not nice as well but if we make it >>> hierarchy specific (which I am proposing for quite some time) and do not >>> let enable accounting for a group with tasks then we get both >>> flexibility and reasonable semantic. A global switch sounds too coars to >>> me and it really not necessary. >>> >>> Would this work with you? >>> >> >> How exactly would that work? AFAIK, we have a single memcg root, we >> can't have multiple memcg hierarchies in a system. Am I missing something? > > Well root is so different that we could consider the first level as the > real roots for hierarchies. > So let's favor clarity: What you are proposing is that the first level can have a switch for that, and the first level only. Is that right ? At first, I just want to understand what exactly is your proposal. This is not an endorsement of lack thereof.