From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with SMTP id 997776B0044 for ; Mon, 14 Dec 2009 20:16:58 -0500 (EST) Received: from m4.gw.fujitsu.co.jp ([10.0.50.74]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id nBF1Gts0025966 for (envelope-from kosaki.motohiro@jp.fujitsu.com); Tue, 15 Dec 2009 10:16:55 +0900 Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id AB24645DE70 for ; Tue, 15 Dec 2009 10:16:55 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 6BC3345DE60 for ; Tue, 15 Dec 2009 10:16:55 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 164B61DB803B for ; Tue, 15 Dec 2009 10:16:55 +0900 (JST) Received: from m107.s.css.fujitsu.com (m107.s.css.fujitsu.com [10.249.87.107]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 7FB0E1DB803A for ; Tue, 15 Dec 2009 10:16:54 +0900 (JST) From: KOSAKI Motohiro Subject: Re: [PATCH 8/8] mm: Give up allocation if the task have fatal signal 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 Date: Tue, 15 Dec 2009 10:16:53 +0900 (JST) Sender: owner-linux-mm@kvack.org To: Minchan Kim 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 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. :) 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, 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