From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pa0-f50.google.com (mail-pa0-f50.google.com [209.85.220.50]) by kanga.kvack.org (Postfix) with ESMTP id B640E6B0257 for ; Thu, 22 Oct 2015 11:15:35 -0400 (EDT) Received: by pabrc13 with SMTP id rc13so89077745pab.0 for ; Thu, 22 Oct 2015 08:15:35 -0700 (PDT) Received: from mail-pa0-x229.google.com (mail-pa0-x229.google.com. [2607:f8b0:400e:c03::229]) by mx.google.com with ESMTPS id gr2si21731677pbc.174.2015.10.22.08.15.34 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 22 Oct 2015 08:15:35 -0700 (PDT) Received: by pabrc13 with SMTP id rc13so89077605pab.0 for ; Thu, 22 Oct 2015 08:15:34 -0700 (PDT) Date: Fri, 23 Oct 2015 00:15:28 +0900 From: Tejun Heo Subject: Re: [PATCH] mm,vmscan: Use accurate values for zone_reclaimable() checks Message-ID: <20151022151528.GG30579@mtj.duckdns.org> References: <20151021143337.GD8805@dhcp22.suse.cz> <20151021145505.GE8805@dhcp22.suse.cz> <201510222037.ACH86458.OFOLFtQFOHJSVM@I-love.SAKURA.ne.jp> <20151022140944.GA30579@mtj.duckdns.org> <20151022150623.GE26854@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20151022150623.GE26854@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Christoph Lameter , Tetsuo Handa , linux-mm@kvack.org, linux-kernel@vger.kernel.org, torvalds@linux-foundation.org, David Rientjes , oleg@redhat.com, kwalker@redhat.com, akpm@linux-foundation.org, hannes@cmpxchg.org, vdavydov@parallels.com, skozina@redhat.com, mgorman@suse.de, riel@redhat.com On Thu, Oct 22, 2015 at 05:06:23PM +0200, Michal Hocko wrote: > Do I get it right that if vmstat_update has its own workqueue with > WQ_MEM_RECLAIM then there is a _guarantee_ that the rescuer will always > be able to process vmstat_update work from the requested CPU? Yeah. > That should be sufficient because vmstat_update doesn't sleep on > allocation. I agree that this would be a more appropriate fix. The problem seems to be reclaim path busy looping waiting for vmstat_update and workqueue thinking that the work item must be making forward-progress and thus not starting the next work item. Thanks. -- tejun -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org