From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail6.bemta12.messagelabs.com (mail6.bemta12.messagelabs.com [216.82.250.247]) by kanga.kvack.org (Postfix) with ESMTP id EB3916B0011 for ; Tue, 24 May 2011 05:06:12 -0400 (EDT) Received: from m4.gw.fujitsu.co.jp (unknown [10.0.50.74]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 07F993EE0BB for ; Tue, 24 May 2011 18:06:10 +0900 (JST) Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id E2EAC45DEC3 for ; Tue, 24 May 2011 18:06:09 +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 CB69445DEC2 for ; Tue, 24 May 2011 18:06:09 +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 BE93B1DB803F for ; Tue, 24 May 2011 18:06:09 +0900 (JST) Received: from m105.s.css.fujitsu.com (m105.s.css.fujitsu.com [10.240.81.145]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id 8606B1DB802F for ; Tue, 24 May 2011 18:06:09 +0900 (JST) Message-ID: <4DDB74F7.9020109@jp.fujitsu.com> Date: Tue, 24 May 2011 18:05:59 +0900 From: KOSAKI Motohiro MIME-Version: 1.0 Subject: Re: Unending loop in __alloc_pages_slowpath following OOM-kill; rfc: patch. References: <4DCDA347.9080207@cray.com> <4DD2991B.5040707@cray.com> <20110520164924.GB2386@barrios-desktop> <4DDB3A1E.6090206@jp.fujitsu.com> <20110524083008.GA5279@suse.de> <4DDB6DF6.2050700@jp.fujitsu.com> <20110524084915.GC5279@suse.de> In-Reply-To: <20110524084915.GC5279@suse.de> Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: mgorman@suse.de Cc: minchan.kim@gmail.com, abarry@cray.com, akpm@linux-foundation.org, linux-mm@kvack.org, riel@redhat.com, hannes@cmpxchg.org, linux-kernel@vger.kernel.org >>> Why? >> >> Otherwise, we don't have good PCP dropping trigger. Big machine might have >> big pcp cache. >> > > Big machines also have a large cost for sending IPIs. Yes. But it's only matter if IPIs are frequently happen. But, drain_all_pages() is NOT only IPI source. some vmscan function (e.g. try_to_umap) makes a lot of IPIs. Then, it's _relatively_ not costly. I have a question. Do you compare which operation and drain_all_pages()? IOW, your "costly" mean which scenario suspect? -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org