From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail190.messagelabs.com (mail190.messagelabs.com [216.82.249.51]) by kanga.kvack.org (Postfix) with SMTP id CE2E36B0044 for ; Mon, 14 Dec 2009 20:09:15 -0500 (EST) Received: by ywh3 with SMTP id 3so3778858ywh.22 for ; Mon, 14 Dec 2009 17:09:14 -0800 (PST) Date: Tue, 15 Dec 2009 10:03:42 +0900 From: Minchan Kim Subject: Re: [PATCH 8/8] mm: Give up allocation if the task have fatal signal Message-Id: <20091215100342.e77c8cbe.minchan.kim@barrios-desktop> In-Reply-To: <20091215094659.CDB8.A69D9226@jp.fujitsu.com> References: <20091214213224.BBC6.A69D9226@jp.fujitsu.com> <20091215085455.13eb65cc.minchan.kim@barrios-desktop> <20091215094659.CDB8.A69D9226@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: KOSAKI Motohiro Cc: Minchan Kim , Rik van Riel , lwoodman@redhat.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: 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. :) -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org