Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752904AbdCPT6J (ORCPT ); Thu, 16 Mar 2017 15:58:09 -0400 Received: from gum.cmpxchg.org ([85.214.110.215]:40708 "EHLO gum.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752510AbdCPT6H (ORCPT ); Thu, 16 Mar 2017 15:58:07 -0400 Date: Thu, 16 Mar 2017 15:57:31 -0400 From: Johannes Weiner To: Shakeel Butt Cc: Yisheng Xie , Andrew Morton , Mel Gorman , Vlastimil Babka , Michal Hocko , riel@redhat.com, Linux MM , LKML , xieyisheng1@huawei.com, guohanjun@huawei.com, Xishi Qiu Subject: Re: [PATCH v2 RFC] mm/vmscan: more restrictive condition for retry in do_try_to_free_pages Message-ID: <20170316195731.GA31479@cmpxchg.org> References: <1489240264-3290-1-git-send-email-ysxie@foxmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.8.0 (2017-02-23) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 911 Lines: 21 On Sat, Mar 11, 2017 at 09:52:15AM -0800, Shakeel Butt wrote: > On Sat, Mar 11, 2017 at 5:51 AM, Yisheng Xie wrote: > > @@ -2808,7 +2826,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, > > return 1; > > > > /* Untapped cgroup reserves? Don't OOM, retry. */ > > - if (!sc->may_thrash) { > > + if (!may_thrash(sc)) { > > Thanks Yisheng. The name of the function may_thrash() is confusing in > the sense that it is returning exactly the opposite of what its name > implies. How about reversing the condition of may_thrash() function > and change the scan_control's field may_thrash to thrashed? How so? The user sets memory.low to a minimum below which the application will thrash. Hence, being allowed to break that minimum and causing the app to thrash, means you "may thrash". OTOH, I'm not sure what "thrashed" would mean.