From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751464AbaIUQAS (ORCPT ); Sun, 21 Sep 2014 12:00:18 -0400 Received: from mail-qc0-f181.google.com ([209.85.216.181]:40496 "EHLO mail-qc0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751204AbaIUQAQ (ORCPT ); Sun, 21 Sep 2014 12:00:16 -0400 Date: Sun, 21 Sep 2014 12:00:12 -0400 From: Tejun Heo To: Vladimir Davydov Cc: Andrew Morton , Johannes Weiner , Michal Hocko , Greg Thelen , Dave Chinner , Glauber Costa , Suleiman Souhlal , Kamezawa Hiroyuki , linux-kernel@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org Subject: Re: [PATCH -mm 00/14] Per memcg slab shrinkers Message-ID: <20140921160012.GA996@mtj.dyndns.org> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Hello, On Sun, Sep 21, 2014 at 07:14:32PM +0400, Vladimir Davydov wrote: ... > list. This is really important, because this allows us to release > memcg_cache_id used for indexing in per-memcg arrays. If we don't do > this, the arrays will grow uncontrollably, which is really bad. Note, in > comparison to user memory reparenting, which Johannes is going to get I don't know the code well and haven't read the patches and could easilya be completely off the mark, but, if the size of slab array is the only issue, wouldn't it be easier to separate that part out? The indexing is only necessary for allocating new items, right? Can't that part be shutdown and the index freed on offline and the rest stay till release? Things like reparenting tends to add fair amount of complexity and hot path overheads which aren't necessary otherwise. Thanks. -- tejun