From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m2.gw.fujitsu.co.jp ([10.0.50.72]) by fgwmail5.fujitsu.co.jp (Fujitsu Gateway) with ESMTP id mA62EA0g030925 for (envelope-from kamezawa.hiroyu@jp.fujitsu.com); Thu, 6 Nov 2008 11:14:10 +0900 Received: from smail (m2 [127.0.0.1]) by outgoing.m2.gw.fujitsu.co.jp (Postfix) with ESMTP id B821345DD87 for ; Thu, 6 Nov 2008 11:14:09 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (s2.gw.fujitsu.co.jp [10.0.50.92]) by m2.gw.fujitsu.co.jp (Postfix) with ESMTP id BC19845DD7F for ; Thu, 6 Nov 2008 11:14:08 +0900 (JST) Received: from s2.gw.fujitsu.co.jp (localhost.localdomain [127.0.0.1]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 8ED051DB8038 for ; Thu, 6 Nov 2008 11:14:08 +0900 (JST) Received: from ml13.s.css.fujitsu.com (ml13.s.css.fujitsu.com [10.249.87.103]) by s2.gw.fujitsu.co.jp (Postfix) with ESMTP id 427431DB803A for ; Thu, 6 Nov 2008 11:14:08 +0900 (JST) Date: Thu, 6 Nov 2008 11:13:32 +0900 From: KAMEZAWA Hiroyuki Subject: Re: [linux-pm] [PATCH] hibernation should work ok with memory hotplug Message-Id: <20081106111332.8d24a11f.kamezawa.hiroyu@jp.fujitsu.com> In-Reply-To: <1225936986.6216.23.camel@nigel-laptop> References: <20081029105956.GA16347@atrey.karlin.mff.cuni.cz> <1225817945.12673.602.camel@nimitz> <20081105093837.e073c373.kamezawa.hiroyu@jp.fujitsu.com> <200811051208.26628.rjw@sisk.pl> <20081106091441.6517c072.kamezawa.hiroyu@jp.fujitsu.com> <1225931281.11514.27.camel@nimitz> <20081106095314.8e65f443.kamezawa.hiroyu@jp.fujitsu.com> <1225936986.6216.23.camel@nigel-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Nigel Cunningham Cc: Dave Hansen , Tolentino , Hansen , linux-pm@lists.osdl.org, Matt@smtp1.linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Dave@smtp1.linux-foundation.org, Mel Gorman , Andy@smtp1.linux-foundation.org, Whitcroft , Yasunori Goto , pavel@suse.cz, Andrew Morton List-ID: On Thu, 06 Nov 2008 13:03:06 +1100 Nigel Cunningham wrote: > Hi. > > On Thu, 2008-11-06 at 09:53 +0900, KAMEZAWA Hiroyuki wrote: > > On Wed, 05 Nov 2008 16:28:01 -0800 > > Dave Hansen wrote: > > > > > On Thu, 2008-11-06 at 09:14 +0900, KAMEZAWA Hiroyuki wrote: > > > > Ok, please consider "when memory hotplug happens." > > > > > > > > In general, it happens when > > > > 1. memory is inserted to slot. > > > > 2. the firmware notifes the system to enable already inserted memory. > > > > > > > > To trigger "1", you have to open cover of server/pc. Do you open pc while the system > > > > starts hibernation ? for usual people, no. > > > > > > You're right, this won't happen very often. We're trying to close a > > > theoretical hole that hasn't ever been observed in practice. But, we > > > don't exactly leave races in code just because we haven't observed them. > > > I think this is a classic race. > > > > > > If we don't close it now, then someone doing some really weirdo hotplug > > > is going to run into it at some point. Who knows what tomorrow's > > > hardware/firmware will do? > > > > > Hmm, people tend to make crazy hardware, oh yes. the pc may fly in the sky with rocket engine. > > It doesn't even have to be crazy. Just imagine someone bumping a button > on the case while plugging in the memory and that button being > configured to make the machine hibernate. > please don't start hibernation if cover is open....(if you can) 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