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=-2.5 required=3.0 tests=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 06DFFC04ABB for ; Tue, 11 Sep 2018 12:47:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A725620833 for ; Tue, 11 Sep 2018 12:47:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A725620833 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 S1727793AbeIKRqu (ORCPT ); Tue, 11 Sep 2018 13:46:50 -0400 Received: from mx2.suse.de ([195.135.220.15]:37664 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726950AbeIKRqu (ORCPT ); Tue, 11 Sep 2018 13:46:50 -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 4451DAF02; Tue, 11 Sep 2018 12:47:38 +0000 (UTC) Date: Tue, 11 Sep 2018 14:47:37 +0200 From: Michal Hocko To: peter enderborg Cc: Roman Gushchin , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, Johannes Weiner , Vladimir Davydov Subject: Re: [PATCH RFC] mm: don't raise MEMCG_OOM event due to failed high-order allocation Message-ID: <20180911124737.GV10951@dhcp22.suse.cz> References: <20180910215622.4428-1-guro@fb.com> <20180911121141.GS10951@dhcp22.suse.cz> <0ea4cdbd-dc3f-1b66-8a5f-8d67ab0e2bc9@sony.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0ea4cdbd-dc3f-1b66-8a5f-8d67ab0e2bc9@sony.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue 11-09-18 14:41:04, peter enderborg wrote: > On 09/11/2018 02:11 PM, Michal Hocko wrote: > > Why is this a problem though? IIRC this event was deliberately placed > > outside of the oom path because we wanted to count allocation failures > > and this is also documented that way > > > > oom > > The number of time the cgroup's memory usage was > > reached the limit and allocation was about to fail. > > > > Depending on context result could be invocation of OOM > > killer and retrying allocation or failing a > > > > One could argue that we do not apply the same logic to GFP_NOWAIT > > requests but in general I would like to see a good reason to change > > the behavior and if it is really the right thing to do then we need to > > update the documentation as well. > > > > Why not introduce a MEMCG_ALLOC_FAIL in to memcg_memory_event? My understanding is that this is what the oom event is about. -- Michal Hocko SUSE Labs