From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753077AbcGVISf (ORCPT ); Fri, 22 Jul 2016 04:18:35 -0400 Received: from mail-wm0-f66.google.com ([74.125.82.66]:35200 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751441AbcGVISb (ORCPT ); Fri, 22 Jul 2016 04:18:31 -0400 Date: Fri, 22 Jul 2016 10:18:28 +0200 From: Michal Hocko To: Vladimir Davydov Cc: Zhou Chengming , linux-kernel@vger.kernel.org, linux-mm@kvack.org, akpm@linux-foundation.org, riel@redhat.com, guohanjun@huawei.com Subject: Re: [PATCH] update sc->nr_reclaimed after each shrink_slab Message-ID: <20160722081828.GE794@dhcp22.suse.cz> References: <1469159010-5636-1-git-send-email-zhouchengming1@huawei.com> <20160722074913.GD794@dhcp22.suse.cz> <20160722081259.GE26049@esperanza> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160722081259.GE26049@esperanza> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 22-07-16 11:12:59, Vladimir Davydov wrote: > On Fri, Jul 22, 2016 at 09:49:13AM +0200, Michal Hocko wrote: > > On Fri 22-07-16 11:43:30, Zhou Chengming wrote: > > > In !global_reclaim(sc) case, we should update sc->nr_reclaimed after each > > > shrink_slab in the loop. Because we need the correct sc->nr_reclaimed > > > value to see if we can break out. > > > > Does this actually change anything? Maybe I am missing something but > > try_to_free_mem_cgroup_pages which is the main entry for the memcg > > reclaim doesn't set reclaim_state. I don't remember why... Vladimir? > > We don't set reclaim_state on memcg reclaim, because there might be a > lot of unrelated slab objects freed from the interrupt context (e.g. > RCU freed) while we're doing memcg reclaim. Obviously, we don't want > them to contribute to nr_reclaimed. > > Link to the thread with the problem discussion: > > http://marc.info/?l=linux-kernel&m=142132698209680&w=2 Ohh, now I rememeber again. Thanks for the refresh ;) So the patch doesn't make any difference in the end. -- Michal Hocko SUSE Labs