From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.4 required=3.0 tests=DATE_IN_PAST_06_12, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9749DC43144 for ; Thu, 28 Jun 2018 19:06:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5BEA927835 for ; Thu, 28 Jun 2018 19:06:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5BEA927835 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030581AbeF1TDn (ORCPT ); Thu, 28 Jun 2018 15:03:43 -0400 Received: from mx2.suse.de ([195.135.220.15]:39018 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S968009AbeF1TDj (ORCPT ); Thu, 28 Jun 2018 15:03:39 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id A414BACFA; Thu, 28 Jun 2018 19:03:35 +0000 (UTC) Date: Thu, 28 Jun 2018 13:39:42 +0200 From: Michal Hocko To: "Paul E. McKenney" Cc: Tetsuo Handa , David Rientjes , linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm,oom: Bring OOM notifier callbacks to outside of OOM killer. Message-ID: <20180628113942.GD32348@dhcp22.suse.cz> References: <1529493638-6389-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp> <20180621073142.GA10465@dhcp22.suse.cz> <2d8c3056-1bc2-9a32-d745-ab328fd587a1@i-love.sakura.ne.jp> <20180626170345.GA3593@linux.vnet.ibm.com> <20180627072207.GB32348@dhcp22.suse.cz> <20180627143125.GW3593@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180627143125.GW3593@linux.vnet.ibm.com> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 27-06-18 07:31:25, Paul E. McKenney wrote: > On Wed, Jun 27, 2018 at 09:22:07AM +0200, Michal Hocko wrote: > > On Tue 26-06-18 10:03:45, Paul E. McKenney wrote: > > [...] > > > 3. Something else? > > > > How hard it would be to use a different API than oom notifiers? E.g. a > > shrinker which just kicks all the pending callbacks if the reclaim > > priority reaches low values (e.g. 0)? > > Beats me. What is a shrinker? ;-) This is a generich mechanism to reclaim memory that is not on standard LRU lists. Lwn.net surely has some nice coverage (e.g. https://lwn.net/Articles/548092/). > More seriously, could you please point me at an exemplary shrinker > use case so I can see what is involved? Well, I am not really sure what is the objective of the oom notifier to point you to the right direction. IIUC you just want to kick callbacks to be handled sooner under a heavy memory pressure, right? How is that achieved? Kick a worker? -- Michal Hocko SUSE Labs