From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761890AbXGOPfl (ORCPT ); Sun, 15 Jul 2007 11:35:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758711AbXGOPfc (ORCPT ); Sun, 15 Jul 2007 11:35:32 -0400 Received: from wa-out-1112.google.com ([209.85.146.179]:48367 "EHLO wa-out-1112.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758635AbXGOPfb (ORCPT ); Sun, 15 Jul 2007 11:35:31 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:user-agent:mime-version:to:cc:subject:references:in-reply-to:x-enigmail-version:openpgp:content-type:content-transfer-encoding; b=UWuzCGbiXUzsf13bk8d9HdNN72fca3moGHwxyLJijzUYUY3dH0tkIda93lMORM1rQflIHhSNTl8zvFxgmJXUtYQOrXUYwk0/a1UIgY98j3BD/kGvBxA/HlfCWluGdhQchgfGmD4dwJ5xQal4ysEXNf++VjaQRAcdw2FygdeEF8o= Message-ID: <469A3EB9.8000304@gmail.com> Date: Sun, 15 Jul 2007 21:05:21 +0530 From: jimmy bahuleyan User-Agent: Thunderbird 2.0.0.4 (X11/20070604) MIME-Version: 1.0 To: Al Boldi CC: "Rafael J. Wysocki" , linux-kernel@vger.kernel.org, Alan Stern , Andrew Morton , "Eric W. Biederman" , "Huang, Ying" , Jeremy Maitin-Shepard , Kyle Moffett , Nigel Cunningham , Pavel Machek , pm list , david@lang.hm Subject: Re: Hibernation considerations References: <200707151433.34625.rjw@sisk.pl> <200707151810.33554.a1426z@gawab.com> In-Reply-To: <200707151810.33554.a1426z@gawab.com> X-Enigmail-Version: 0.95.2 OpenPGP: url=subkeys.pgp.net Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Al Boldi wrote: > > This should be the responsibility of the kexec'd hibernating kernel. Note > though in (6), the normal kernel takes care of preparing devices, then the > hibernating kernel dumps the image and either calls S4 or S3. On resume > from S3 it can immediately switch over to the normal kernel, and from S4 the > known bootup would occur. > >> (8) Hibernation and restore should not be too slow >> >> In my opinion, if more than one minute is needed to hibernate the >> system with the help of certain hibernation framework, then this framework >> is not very useful in practice. It might be useful to perform some >> special tasks (eg. moving a server to another place without taking it >> down), but it is not very useful, for example, to notebook users. > > The latest hibernating kexec patches boot a kexec'd modular kernel with > initramfs into crashkernel=16M@16M in less than one second. Switch-back is > almost instant. Add to this the time required to either store or restore > the image, and it may be obvious that this approach isn't slower, but maybe > even faster than the current swsusp. > What about (9)? Would it be that a user choosing to build a kernel with hibernate support gets a additional modular kernel built (which he should then use for resumption) or he should configure & build the modular kernel independent of main kernel? Or will the Linux boot procedure change so that it always goes thru a modular part followed by kexec (just to be uniform)? Although the kexec approach seems interesting, the final user-scenario seems a bit complex (or confusing). -jb -- Tact is the art of making a point without making an enemy.