Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757159AbYCMXMh (ORCPT ); Thu, 13 Mar 2008 19:12:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752602AbYCMXM3 (ORCPT ); Thu, 13 Mar 2008 19:12:29 -0400 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:42078 "EHLO ebiederm.dsl.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752194AbYCMXM2 (ORCPT ); Thu, 13 Mar 2008 19:12:28 -0400 From: ebiederm@xmission.com (Eric W. Biederman) To: "Rafael J. Wysocki" Cc: Alan Stern , "Huang, Ying" , nigel@nigel.suspend2.net, Kexec Mailing List , linux-kernel@vger.kernel.org, Andrew Morton , linux-pm@lists.linux-foundation.org, Vivek Goyal Subject: Re: [linux-pm] [PATCH -mm] kexec jump -v9 References: <200803122253.07631.rjw@sisk.pl> <200803131803.31120.rjw@sisk.pl> Date: Thu, 13 Mar 2008 17:07:17 -0600 In-Reply-To: <200803131803.31120.rjw@sisk.pl> (Rafael J. Wysocki's message of "Thu, 13 Mar 2008 18:03:29 +0100") Message-ID: User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1295 Lines: 30 "Rafael J. Wysocki" writes: > From the ACPI compliance point of view it's better to do it this way. We need > to put the devices into low power states anyway before "powering off" the > system and we won't need to touch them for the second time if we do that > in advance. Interesting. From a kexec jump where we exit the kernel and then return to it seem all that is required. I will have to look at the ACPI case. That seems to be the lynch pin of a couple of arguments for doing strange things: ACPI requires it. > Still, it would be sufficient if we disconnected the drivers from the hardware > and thus prevented applications from accessing that hardware. My gut feeling is that except for a handful of drivers we could even get away with simply implementing hot unplug and hot replug. Disks are the big exception here. Which suggests to me that it is at least possible that the methods we want for a kexec jump hibernation may be different from an in-kernel hibernation and quite possibly are easier to implement. Eric -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/