From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: [RFC][PATCH 2/2] first callers of process_deny_checkpoint() Date: Fri, 10 Oct 2008 21:53:39 +0200 Message-ID: <20081010195339.GA509@elte.hu> References: <20081009190405.13A253CB@kernel> <200810101517.17809.rjw@sisk.pl> <20081010145422.GE11695@elte.hu> <200810102153.45174.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mx2.mail.elte.hu ([157.181.151.9]:37983 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761147AbYJJTyP (ORCPT ); Fri, 10 Oct 2008 15:54:15 -0400 Content-Disposition: inline In-Reply-To: <200810102153.45174.rjw@sisk.pl> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: "Rafael J. Wysocki" Cc: Dave Hansen , "Serge E. Hallyn" , containers@lists.linux-foundation.org, arnd@arndb.de, linux-kernel@vger.kernel.org, Arjan van de Ven , Peter Zijlstra , ACPI Devel Maling List * Rafael J. Wysocki wrote: > > > Surely not ACPI-compliant. > > > > what do you mean? > > The ACPI spec says quite specifically what should be done while > entering hibernation and during resume from hibernation. We're not > following that in the current code, but we can (gradually) update the > code to become ACPI-compilant in that respect. However, if we go the > checkpointing route, I don't think that will be possible any more. ah, i see. I did not mean to utilize any ACPI paths but simple powerdown or reboot. If we checkpoint all apps to persistent disk areas (which the checkpoint patches in this thread are about), then we can just reboot the kernel and forget all its state. That capability can be used to build a really robust hibernation implementation IMO: we could "hibernate/kexec" over between different kernel versions transparently. (only a small delay will be noticed by the user - if we do it smartly with in-kernel modesetting then not even the screen contents will be changed over this.) Ingo