From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751325AbWGKWdx (ORCPT ); Tue, 11 Jul 2006 18:33:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751336AbWGKWdx (ORCPT ); Tue, 11 Jul 2006 18:33:53 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:64988 "EHLO ogre.sisk.pl") by vger.kernel.org with ESMTP id S1751325AbWGKWdw (ORCPT ); Tue, 11 Jul 2006 18:33:52 -0400 From: "Rafael J. Wysocki" To: Nigel Cunningham Subject: Re: uswsusp history lesson [was Re: [Suspend2-devel] Re: swsusp / suspend2 reliability] Date: Wed, 12 Jul 2006 00:34:01 +0200 User-Agent: KMail/1.9.3 Cc: Pavel Machek , suspend2-devel@lists.suspend2.net, Olivier Galibert , grundig , Avuton Olrich , jan@rychter.com, linux-kernel@vger.kernel.org References: <20060627133321.GB3019@elf.ucw.cz> <200607112354.56078.rjw@sisk.pl> <200607120801.24239.ncunningham@linuxmail.org> In-Reply-To: <200607120801.24239.ncunningham@linuxmail.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200607120034.01339.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 12 July 2006 00:01, Nigel Cunningham wrote: > On Wednesday 12 July 2006 07:54, Rafael J. Wysocki wrote: > > On Tuesday 11 July 2006 14:45, Nigel Cunningham wrote: > > > On Sunday 09 July 2006 04:52, Rafael J. Wysocki wrote: > > > > Well, I tried really hard to justify the patch that allowed swsusp to > > > > create bigger images and 10% was the greatest speedup I could get out > > > > of it and, let me repeat, _with_ compression and async I/O. I tried to > > > > simulate different workloads etc., but I couldn't get more than 10% > > > > speedup (the biggest image I got was as big as 80% of RAM) - counting > > > > the time from issuing the suspend command to getting back _responsive_ > > > > system after resume. > > > > > > Was that 10% speedup on suspend or resume, or both? With LZF, I see > > > approximately double the speed with both reading and writing: > > > > I was not referring to the speedup of writing and/or reading. > > > > The exercise was to measure the time needed to suspend the system and get > > it back in a responsive state. I measured the time elapsed between > > triggering the suspend and the moment at which I could switch between some > > applications in X without any noticeable lag due to faulting in some pages > > (that is a bit subjective, I must admit, but I was willing to show that > > bigger images make substantial difference). > > > > I tested uswsusp with compression (LZF) and two image sizes: 120 MB and > > (IIRC) about 220 MB on a 256 MB box. The result of the measurement for the > > 120 MB image has always been greater than for the 220 MB image, but the > > difference has never been greater than 10%. > > Ah ok. Are you sure you're getting that sort of throughput with LZF though - > if you're not, you might be underestimating the advantage. Certainly I don't get that kind of speedup for writing. For reading I do. Greetings, Rafael