From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with SMTP id 6BA906B0078 for ; Mon, 6 Sep 2010 04:18:25 -0400 (EDT) Received: from m4.gw.fujitsu.co.jp ([10.0.50.74]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id o868IMt2003091 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Mon, 6 Sep 2010 17:18:23 +0900 Received: from smail (m4 [127.0.0.1]) by outgoing.m4.gw.fujitsu.co.jp (Postfix) with ESMTP id 4C11545DE79 for ; Mon, 6 Sep 2010 17:18:22 +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 242C845DE6F for ; Mon, 6 Sep 2010 17:18:22 +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 F2A5B1DB8040 for ; Mon, 6 Sep 2010 17:18:21 +0900 (JST) Received: from m108.s.css.fujitsu.com (m108.s.css.fujitsu.com [10.249.87.108]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id ABA051DB803B for ; Mon, 6 Sep 2010 17:18:21 +0900 (JST) Date: Mon, 6 Sep 2010 17:13:07 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [PATCH 1/4] swap: revert special hibernation allocation Message-Id: <20100906171307.9e8d9637.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Hugh Dickins Cc: Andrew Morton , KOSAKI Motohiro , "Rafael J. Wysocki" , Ondrej Zary , Andrea Gelmini , Balbir Singh , Andrea Arcangeli , Nigel Cunningham , linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Mon, 6 Sep 2010 01:10:55 -0700 (PDT) Hugh Dickins wrote: > Please revert 2.6.36-rc commit d2997b1042ec150616c1963b5e5e919ffd0b0ebf > "hibernation: freeze swap at hibernation". It complicated matters by > adding a second swap allocation path, just for hibernation; without in > any way fixing the issue that it was intended to address - page reclaim > after fixing the hibernation image might free swap from a page already > imaged as swapcache, letting its swap be reallocated to store a different > page of the image: resulting in data corruption if the imaged page were > freed as clean then swapped back in. Pages freed to si->swap_map were > still in danger of being reallocated by the alternative allocation path. > > I guess it inadvertently fixed slow SSD swap allocation for hibernation, > as reported by Nigel Cunningham: by missing out the discards that occur > on the usual swap allocation path; but that was unintentional, and needs > a separate fix. > > Signed-off-by: Hugh Dickins > Cc: KAMEZAWA Hiroyuki > Cc: KOSAKI Motohiro > Cc: "Rafael J. Wysocki" > Cc: Ondrej Zary > Cc: Andrea Gelmini > Cc: Balbir Singh > Cc: Andrea Arcangeli > Cc: Nigel Cunningham Acked-by: KAMEZAWA Hiroyuki -- 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