From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751140AbdBBKOU (ORCPT ); Thu, 2 Feb 2017 05:14:20 -0500 Received: from mx2.suse.de ([195.135.220.15]:43876 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751002AbdBBKOS (ORCPT ); Thu, 2 Feb 2017 05:14:18 -0500 Date: Thu, 2 Feb 2017 11:14:15 +0100 From: Michal Hocko To: Tetsuo Handa Cc: hch@lst.de, mgorman@suse.de, viro@ZenIV.linux.org.uk, linux-mm@kvack.org, hannes@cmpxchg.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages per zone Message-ID: <20170202101415.GE22806@dhcp22.suse.cz> References: <20170125101957.GA17632@lst.de> <20170125104605.GI32377@dhcp22.suse.cz> <201701252009.IHG13512.OFOJFSVLtOQMFH@I-love.SAKURA.ne.jp> <20170125130014.GO32377@dhcp22.suse.cz> <20170127144906.GB4148@dhcp22.suse.cz> <201701290027.AFB30799.FVtFLOOOJMSHQF@I-love.SAKURA.ne.jp> <20170130085546.GF8443@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170130085546.GF8443@dhcp22.suse.cz> 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 Mon 30-01-17 09:55:46, Michal Hocko wrote: > On Sun 29-01-17 00:27:27, Tetsuo Handa wrote: [...] > > Regarding [1], it helped avoiding the too_many_isolated() issue. I can't > > tell whether it has any negative effect, but I got on the first trial that > > all allocating threads are blocked on wait_for_completion() from flush_work() > > in drain_all_pages() introduced by "mm, page_alloc: drain per-cpu pages from > > workqueue context". There was no warn_alloc() stall warning message afterwords. > > That patch is buggy and there is a follow up [1] which is not sitting in the > mmotm (and thus linux-next) yet. I didn't get to review it properly and > I cannot say I would be too happy about using WQ from the page > allocator. I believe even the follow up needs to have WQ_RECLAIM WQ. > > [1] http://lkml.kernel.org/r/20170125083038.rzb5f43nptmk7aed@techsingularity.net Did you get chance to test with this follow up patch? It would be interesting to see whether OOM situation can still starve the waiter. The current linux-next should contain this patch. Thanks! -- Michal Hocko SUSE Labs