From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933602AbXDZIXk (ORCPT ); Thu, 26 Apr 2007 04:23:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933604AbXDZIXk (ORCPT ); Thu, 26 Apr 2007 04:23:40 -0400 Received: from ug-out-1314.google.com ([66.249.92.172]:16779 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933602AbXDZIXf (ORCPT ); Thu, 26 Apr 2007 04:23:35 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references:x-google-sender-auth; b=GvIOQekLSAjqj6nr3hD7raIdBnb8OhpSjqjt+poa6yJGrJRbpqO65sLWGYQIN1MrwgQvyFLyOwq/HEIMg9i+fL6IWHxPzLAZOTtwXVe4aBvA14CahTLpbkX4x2LXUarDOlGwvkQ51zKqCOURgYIF5NOyWyo3Foqaemybvj6ZbFk= Message-ID: <84144f020704260117l3794ebe3q7aaa49bc98888d01@mail.gmail.com> Date: Thu, 26 Apr 2007 11:17:17 +0300 From: "Pekka Enberg" To: nigel@nigel.suspend2.net Subject: Re: Back to the future. Cc: "Linus Torvalds" , LKML In-Reply-To: <1177573348.5025.224.camel@nigel.suspend2.net> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <1177567481.5025.211.camel@nigel.suspend2.net> <84144f020704260028q190fc90fs8f9ea703e42e7910@mail.gmail.com> <1177573348.5025.224.camel@nigel.suspend2.net> X-Google-Sender-Auth: 2823bad3edcf6330 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi Nigel, On 4/26/07, Nigel Cunningham wrote: > * Doing things in the right order? (Prepare the image, then do the > atomic copy, then save). As I am a total newbie to the power management code, I am unable to spot the conceptual difference in uswsusp suspend.c:suspend_system() and suspend2 kernel/power/suspend.c:suspend_main(). How are they different? On 4/26/07, Nigel Cunningham wrote: > * Mulithreaded I/O (might as well use multiple cores to compress the > image, now that we're hotplugging later). I assume this doesn't affect the kernel at all with uswsusp? On 4/26/07, Nigel Cunningham wrote: > * Modular design? This is too broad. Please be more specific of the problems the current suspend and snapshot/shutdown code in the kernel has. Now to add to your list, as far as I can tell, suspend2 provides better feedback to the user via the netlink mechanism (although the kernel shouldn't be sending messages such as userui_redraw but instead let the userspace know of the actual events, for example, that tasks have now been frozen). However, I am unsure if this is still relevant as most of the work (snapshot writing) is being done in userspace where we explicitly know when processes have been frozen, when the snapshot is finished, and when it's written to disk. Pekka