From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with SMTP id 6A7636B009D for ; Sun, 24 Oct 2010 23:14:29 -0400 (EDT) Received: from m6.gw.fujitsu.co.jp ([10.0.50.76]) by fgwmail7.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o9P3EPLK017644 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Mon, 25 Oct 2010 12:14:25 +0900 Received: from smail (m6 [127.0.0.1]) by outgoing.m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 416F145DE51 for ; Mon, 25 Oct 2010 12:14:25 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (s6.gw.fujitsu.co.jp [10.0.50.96]) by m6.gw.fujitsu.co.jp (Postfix) with ESMTP id 1E1121EF081 for ; Mon, 25 Oct 2010 12:14:25 +0900 (JST) Received: from s6.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id EFA60E38002 for ; Mon, 25 Oct 2010 12:14:24 +0900 (JST) Received: from ml14.s.css.fujitsu.com (ml14.s.css.fujitsu.com [10.249.87.104]) by s6.gw.fujitsu.co.jp (Postfix) with ESMTP id A3DA81DB8014 for ; Mon, 25 Oct 2010 12:14:24 +0900 (JST) Date: Mon, 25 Oct 2010 12:09:01 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH] do_migrate_range: avoid failure as much as possible Message-Id: <20101025120901.88fdbd17.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <20101025120550.45745c3d.kamezawa.hiroyu@jp.fujitsu.com> References: <1287974851-4064-1-git-send-email-lliubbo@gmail.com> <20101025114017.86ee5e54.kamezawa.hiroyu@jp.fujitsu.com> <20101025025703.GA13858@localhost> <20101025120550.45745c3d.kamezawa.hiroyu@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: KAMEZAWA Hiroyuki Cc: Wu Fengguang , Bob Liu , "akpm@linux-foundation.org" , "linux-mm@kvack.org" , "mel@csn.ul.ie" , "kosaki.motohiro@jp.fujitsu.com" List-ID: On Mon, 25 Oct 2010 12:05:50 +0900 KAMEZAWA Hiroyuki wrote: > This changes behavior. > > This "ret" can be > 0 because migrate_page()'s return code is > "Return: Number of pages not migrated or error code." > > Then, > ret < 0 ===> maybe ebusy > ret > 0 ===> some pages are not migrated. maybe PG_writeback or some > ret == 0 ===> ok, all condition green. try next chunk soon. > > Then, I added "yield()" and --retrym_max for !ret cases. ^^^^^^^^ wrong. The code here does ret == 0 ==> ok, all condition green, try next chunk. ret > 0 ==> all pages are isolated but some pages cannot be migrated. maybe under I/O do yield. ret < 0 ==> some pages may not be able to be isolated. reduce retrycount and yield() Thanks, -Kame -- 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