Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932408Ab0BDVjR (ORCPT ); Thu, 4 Feb 2010 16:39:17 -0500 Received: from smtp-out.google.com ([216.239.44.51]:57709 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756327Ab0BDVjP (ORCPT ); Thu, 4 Feb 2010 16:39:15 -0500 DomainKey-Signature: a=rsa-sha1; s=beta; d=google.com; c=nofws; q=dns; h=date:from:x-x-sender:to:cc:subject:in-reply-to:message-id: references:user-agent:mime-version:content-type:x-system-of-record; b=FVGtdMCC09WhynwupE6BVJ6Oh/ulUbtnM3Lzrj3uoy+tTHJIswPD2GfK6pdi8sm2O xKYiWlfKUUERjlGNSv1Ww== Date: Thu, 4 Feb 2010 13:39:08 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Jiri Kosina cc: Lubos Lunak , Balbir Singh , Rik van Riel , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , KOSAKI Motohiro , Nick Piggin Subject: Re: Improving OOM killer In-Reply-To: Message-ID: References: <201002012302.37380.l.lunak@suse.cz> <20100203170127.GH19641@balbir.in.ibm.com> <201002032355.01260.l.lunak@suse.cz> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1254 Lines: 27 On Thu, 4 Feb 2010, Jiri Kosina wrote: > Why does OOM killer care about forkbombs *at all*? > Because the cumulative effects of a forkbomb are detrimental to the system and the badness() heursitic favors large memory consumers very heavily. Thus, the forkbomb is never really a strong candidate for oom kill since the parent may consume very little memory itself and meanwhile KDE or another large memory consumer will get innocently killed instead as a result. > If we really want kernel to detect forkbombs (*), we'd have to establish > completely separate infrastructure for that (with its own knobs for tuning > and possibilities of disabling it completely). > That's what we're trying to do, we can look at the shear number of children that the parent has forked and check for it to be over a certain "forkbombing threshold" (which, yes, can be tuned from userspace), the uptime of those children, their resident set size, etc., to attempt to find a sane heuristic that penalizes them. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/