Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755060AbdDKMas (ORCPT ); Tue, 11 Apr 2017 08:30:48 -0400 Received: from mx2.suse.de ([195.135.220.15]:40834 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755011AbdDKMal (ORCPT ); Tue, 11 Apr 2017 08:30:41 -0400 Date: Tue, 11 Apr 2017 14:30:26 +0200 From: Michal Hocko To: Johannes Weiner Cc: Andrew Morton , Vladimir Davydov , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH 2/4] mm: memcontrol: re-use global VM event enum Message-ID: <20170411123025.GL6729@dhcp22.suse.cz> References: <20170404220148.28338-1-hannes@cmpxchg.org> <20170404220148.28338-2-hannes@cmpxchg.org> <20170407124702.GE16413@dhcp22.suse.cz> <20170410141334.GA16119@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170410141334.GA16119@cmpxchg.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1935 Lines: 61 On Mon 10-04-17 10:13:34, Johannes Weiner wrote: > On Fri, Apr 07, 2017 at 02:47:02PM +0200, Michal Hocko wrote: > > I do agree that we should share global and memcg specific events constants > > but I am not sure we want to share all of them. Would it make sense to > > reorganize the global enum and put those that are shared to the > > beginning? We wouldn't need the memcg specific translation then. > > I'm not sure I follow. Which translation? Sorry, I should have said s@translation@filtering@ by memcg1_events* > > Anyway, two comments on the current implementation. > > > > On Tue 04-04-17 18:01:46, Johannes Weiner wrote: > > [...] > > > +/* Cgroup-specific events, on top of universal VM events */ > > > +enum memcg_event_item { > > > + MEMCG_LOW = NR_VM_EVENT_ITEMS, > > > + MEMCG_HIGH, > > > + MEMCG_MAX, > > > + MEMCG_OOM, > > > + MEMCG_NR_EVENTS, > > > +}; > > > > The above should mention that each supported global VM event should > > provide the corresponding translation > > > > [...] > > > > here... > > > +/* Universal VM events cgroup1 shows, original sort order */ > > > +unsigned int memcg1_events[] = { > > > + PGPGIN, > > > + PGPGOUT, > > > + PGFAULT, > > > + PGMAJFAULT, > > > +}; > > > + > > > +static const char *const memcg1_event_names[] = { > > > + "pgpgin", > > > + "pgpgout", > > > + "pgfault", > > > + "pgmajfault", > > > +}; > > > > the naming doesn't make it easier to undestand why we need this. > > global2memcg_event? > > This is just to keep the file order consistent. It could have been > done like memory.stat in cgroup2, where we simply do > > seq_printf(s, "pgmajfault %lu\n", stat[PGMAJFAULT]); > > but I didn't want to change the v1 code too much. So these two arrays > are just a sorted list of global VM events shown in v1's memory.stat. You would still have to know which are the relevant parts of the global starts that we account for memcg. -- Michal Hocko SUSE Labs