Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758948AbZLOBQ6 (ORCPT ); Mon, 14 Dec 2009 20:16:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758931AbZLOBQ5 (ORCPT ); Mon, 14 Dec 2009 20:16:57 -0500 Received: from fgwmail5.fujitsu.co.jp ([192.51.44.35]:52214 "EHLO fgwmail5.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758533AbZLOBQ4 (ORCPT ); Mon, 14 Dec 2009 20:16:56 -0500 X-SecurityPolicyCheck-FJ: OK by FujitsuOutboundMailChecker v1.3.1 From: KOSAKI Motohiro To: Minchan Kim Subject: Re: [PATCH 8/8] mm: Give up allocation if the task have fatal signal Cc: kosaki.motohiro@jp.fujitsu.com, Rik van Riel , lwoodman@redhat.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org In-Reply-To: <20091215100342.e77c8cbe.minchan.kim@barrios-desktop> References: <20091215094659.CDB8.A69D9226@jp.fujitsu.com> <20091215100342.e77c8cbe.minchan.kim@barrios-desktop> Message-Id: <20091215101512.CDC4.A69D9226@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver. 2.50.07 [ja] Date: Tue, 15 Dec 2009 10:16:53 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1499 Lines: 46 > On Tue, 15 Dec 2009 09:50:47 +0900 (JST) > KOSAKI Motohiro wrote: > > > > > /* > > > > + * If the allocation is for userland page and we have fatal signal, > > > > + * there isn't any reason to continue allocation. instead, the task > > > > + * should exit soon. > > > > + */ > > > > + if (fatal_signal_pending(current) && (gfp_mask & __GFP_HIGHMEM)) > > > > + goto nopage; > > > > > > If we jump nopage, we meets dump_stack and show_mem. > > > Even, we can meet OOM which might kill innocent process. > > > > Which point you oppose? noprint is better? > > > > > > Sorry fot not clarity. > My point was following as. > > First, > I don't want to print. > Why do we print stack and mem when the process receives the SIGKILL? > > Second, > 1) A process try to allocate anon page in do_anonymous_page. > 2) A process receives SIGKILL. > 3) kernel doesn't allocate page to A process by your patch. > 4) do_anonymous_page returns VF_FAULT_OOM. > 5) call mm_fault_error > 6) call out_of_memory > 7) It migth kill innocent task. > > If I missed something, Pz, corret me. :) Doh, you are complely right. I had forgot recent meaning change of VM_FAULT_OOM. yes, this patch is crap. I need to remake it. -- 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/