Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755194AbYCLVyR (ORCPT ); Wed, 12 Mar 2008 17:54:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752637AbYCLVyF (ORCPT ); Wed, 12 Mar 2008 17:54:05 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:44138 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752425AbYCLVyE (ORCPT ); Wed, 12 Mar 2008 17:54:04 -0400 From: "Rafael J. Wysocki" To: Alan Stern Subject: Re: [linux-pm] [PATCH -mm] kexec jump -v9 Date: Wed, 12 Mar 2008 22:53:06 +0100 User-Agent: KMail/1.9.6 (enterprise 20070904.708012) Cc: "Huang, Ying" , nigel@nigel.suspend2.net, Kexec Mailing List , linux-kernel@vger.kernel.org, "Eric W. Biederman" , Andrew Morton , linux-pm@lists.linux-foundation.org, Vivek Goyal References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200803122253.07631.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1410 Lines: 35 On Wednesday, 12 of March 2008, Alan Stern wrote: > On Wed, 12 Mar 2008, Huang, Ying wrote: > > > I think "kexec based hibernation" is the only currently available > > possible method to write out image without freezer (after driver works > > are done). If other process is running, how to prevent them from writing > > to disk without freezing them in current implementation? > > This is a very good question. > > It's a matter of managing the block layer's request queues. Somehow > the existing I/O requests must remain blocked while the requests needed > for writing the image must be allowed to proceed. > > I don't know what would be needed to make this work, but it ought to be > possible somehow... Yes, it ought to be possible. Ultimately, IMHO, we should put all devices unnecessary for saving the image (and doing some eye-candy work) into low power states before the image is created and keep them in low power states until the system is eventually powered off. If this is done, the remaining problem is the handling of the devices that we need to save the image. I believe that will be achievable without using the freezer. Thanks, Rafael -- 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/