From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261785AbULJSQP (ORCPT ); Fri, 10 Dec 2004 13:16:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261784AbULJSQP (ORCPT ); Fri, 10 Dec 2004 13:16:15 -0500 Received: from mail-relay-2.tiscali.it ([213.205.33.42]:25219 "EHLO mail-relay-2.tiscali.it") by vger.kernel.org with ESMTP id S261785AbULJSQM (ORCPT ); Fri, 10 Dec 2004 13:16:12 -0500 Date: Fri, 10 Dec 2004 19:15:29 +0100 From: Andrea Arcangeli To: William Lee Irwin III Cc: Thomas Gleixner , Andrew Morton , marcelo.tosatti@cyclades.com, LKML , nickpiggin@yahoo.com.au Subject: Re: [PATCH] oom killer (Core) Message-ID: <20041210181529.GZ16322@dualathlon.random> References: <20041202085518.58e0e8eb.akpm@osdl.org> <20041202180823.GD32635@dualathlon.random> <1102013716.13353.226.camel@tglx.tec.linutronix.de> <20041202233459.GF32635@dualathlon.random> <20041203022854.GL32635@dualathlon.random> <20041210163614.GN2714@holomorphy.com> <20041210173554.GW16322@dualathlon.random> <20041210174336.GP2714@holomorphy.com> <20041210175504.GY16322@dualathlon.random> <20041210180031.GT2714@holomorphy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20041210180031.GT2714@holomorphy.com> X-GPG-Key: 1024D/68B9CB43 13D9 8355 295F 4823 7C49 C012 DFA1 686E 68B9 CB43 X-PGP-Key: 1024R/CB4660B9 CC A0 71 81 F4 A0 63 AC C0 4B 81 1D 8C 15 C8 E5 User-Agent: Mutt/1.5.6i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 10, 2004 at 10:00:31AM -0800, William Lee Irwin III wrote: > Yet those don't appear in the tasklist, so some task in the tasklist > has to get ->mm set to &init_mm. The notion above was that the init_mm > check was to handle some out-of-tree attempt to do aio from kernel threads. Not sure to understand correctly but, aio has always been done through kernel threads, and that's the whole thing about aio. Not sure what you're doing out-of-tree, but you don't need to use init_mm to deal with kernel threads, infact kernel threads can only have ->mm = NULL. When switching mm with use_mm the aio thread is only going to use a real mm with mappings in userspace, so even in that case you don't need init_mm. I didn't see the out of tree code though.