From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753427AbcEMPPb (ORCPT ); Fri, 13 May 2016 11:15:31 -0400 Received: from smtpoutz27.laposte.net ([194.117.213.102]:48019 "EHLO smtp.laposte.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753310AbcEMPP3 (ORCPT ); Fri, 13 May 2016 11:15:29 -0400 Message-ID: <5735EF8E.4000707@laposte.net> Date: Fri, 13 May 2016 17:15:26 +0200 From: Sebastian Frias User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: One Thousand Gnomes CC: "Austin S. Hemmelgarn" , Michal Hocko , Mason , linux-mm@kvack.org, Andrew Morton , Linus Torvalds , LKML Subject: Re: [PATCH] mm: add config option to select the initial overcommit mode References: <5731CC6E.3080807@laposte.net> <20160513080458.GF20141@dhcp22.suse.cz> <573593EE.6010502@free.fr> <5735A3DE.9030100@laposte.net> <20160513120042.GK20141@dhcp22.suse.cz> <5735CAE5.5010104@laposte.net> <935da2a3-1fda-bc71-48a5-bb212db305de@gmail.com> <5735D7FC.3070409@laposte.net> <20160513160142.2cc7d695@lxorguk.ukuu.org.uk> In-Reply-To: <20160513160142.2cc7d695@lxorguk.ukuu.org.uk> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-VR-SrcIP: 83.142.147.193 X-VR-FullState: 0 X-VR-Score: -100 X-VR-Cause-1: gggruggvucftvghtrhhoucdtuddrfeekledrvddugdekhecutefuodetggdotefrodftvfcurfhrohhf X-VR-Cause-2: ihhlvgemucfntefrqffuvffgnecuuegrihhlohhuthemucehtddtnecusecvtfgvtghiphhivghnthhs X-VR-Cause-3: ucdlqddutddtmdenucfjughrpefkfffhfgggvffufhgjtgfgsehtjegrtddtfeehnecuhfhrohhmpefu X-VR-Cause-4: vggsrghsthhirghnucfhrhhirghsuceoshhfkeegsehlrghpohhsthgvrdhnvghtqeenucfkphepkeef X-VR-Cause-5: rddugedvrddugeejrdduleefnecurfgrrhgrmhepmhhouggvpehsmhhtphhouhhtpdhhvghloheplgdu X-VR-Cause-6: jedvrddvjedrtddrvddugegnpdhinhgvthepkeefrddugedvrddugeejrdduleefpdhmrghilhhfrhho X-VR-Cause-7: mhepshhfkeegsehlrghpohhsthgvrdhnvghtpdhrtghpthhtohepghhnohhmvghssehlgihorhhguhhk X-VR-Cause-8: rdhukhhuuhdrohhrghdruhhk X-VR-AvState: No X-VR-State: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Alan, On 05/13/2016 05:01 PM, One Thousand Gnomes wrote: > On Fri, 13 May 2016 15:34:52 +0200 > Sebastian Frias wrote: > >> Hi Austin, >> >> On 05/13/2016 03:11 PM, Austin S. Hemmelgarn wrote: >>> On 2016-05-13 08:39, Sebastian Frias wrote: >>>> >>>> My point is that it seems to be possible to deal with such conditions in a more controlled way, ie: a way that is less random and less abrupt. >>> There's an option for the OOM-killer to just kill the allocating task instead of using the scoring heuristic. This is about as deterministic as things can get though. >> >> By the way, why does it has to "kill" anything in that case? >> I mean, shouldn't it just tell the allocating task that there's not enough memory by letting malloc return NULL? > > Just turn off overcommit and it will do that. With overcommit disabled > the kernel will not hand out address space in excess of memory plus swap. I think I'm confused. Michal just said: "And again, overcommit=never doesn't imply no-OOM. It just makes it less likely. The kernel can consume quite some unreclaimable memory as well." which I understand as the OOM-killer will still lurk around and could still wake up. Will overcommit=never totally disable the OOM-Killer or not? Best regards, Sebastian