From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933511AbXGLP2d (ORCPT ); Thu, 12 Jul 2007 11:28:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758910AbXGLP20 (ORCPT ); Thu, 12 Jul 2007 11:28:26 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:55670 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758470AbXGLP2Z (ORCPT ); Thu, 12 Jul 2007 11:28:25 -0400 From: "Rafael J. Wysocki" To: Mark Lord Subject: Re: [PATCH 0/2] Kexec jump: The first step to kexec base hibernation Date: Thu, 12 Jul 2007 17:35:38 +0200 User-Agent: KMail/1.9.5 Cc: david@lang.hm, Jeremy Fitzhardinge , Andrew Morton , "Huang, Ying" , Pavel Machek , nigel@nigel.suspend2.net, Jeremy Maitin-Shepard , linux-kernel@vger.kernel.org, linux-pm@lists.linux-foundation.org References: <1184167831.12556.13.camel@caritas-dev.intel.com> <200707121446.14170.rjw@sisk.pl> <469631FA.2070405@rtr.ca> In-Reply-To: <469631FA.2070405@rtr.ca> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200707121735.40077.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, 12 July 2007 15:51, Mark Lord wrote: > Rafael J. Wysocki wrote: > > On Thursday, 12 July 2007 08:43, david@lang.hm wrote: > >> On Wed, 11 Jul 2007, Jeremy Fitzhardinge wrote: > >> > >>> Andrew Morton wrote: > .. > >> 8. hibernate kernel does syspend-to-ram to put the devices into a known > >> safe state. > > Again, the devices should be quiesced rather then suspended in this step. > > That's just not possible. The Hibernate kernel will not have all > of the same device drivers as the mainline kernel. Or at least that's > what people have previously stated here. OK, one more problem to solve. :-) > >>>> This sounds awesome. Am I correct in expecting that ultimately the > >>>> existing hibernation implementation just goes away and we reuse (and hence > >>>> strengthen) the existing kexec (and kdump?) infrastructure? > > No, not so simple. We still need much of the code to santize devices > upon wakeup from hibernation. And adding this extra reboot-kernel step > in the midst of hibernate will double the time it takes (ugh). > > Currently, TuxOnIce(suspend2) takes about 10 seconds to suspend my notebook. > Switching to this new scheme would double that to 10 seconds to boot/probe, > plus the original 10 seconds to hibernate. Assuming the new implementation > even comes close to suspend2 speed. How much RAM is there in your machine? Greetings, Rafael -- "Premature optimization is the root of all evil." - Donald Knuth