From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932158AbWGKVyt (ORCPT ); Tue, 11 Jul 2006 17:54:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932159AbWGKVys (ORCPT ); Tue, 11 Jul 2006 17:54:48 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:24284 "EHLO ogre.sisk.pl") by vger.kernel.org with ESMTP id S932158AbWGKVyr (ORCPT ); Tue, 11 Jul 2006 17:54:47 -0400 From: "Rafael J. Wysocki" To: Nigel Cunningham Subject: Re: uswsusp history lesson [was Re: [Suspend2-devel] Re: swsusp / suspend2 reliability] Date: Tue, 11 Jul 2006 23:54:55 +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> <200607082052.02557.rjw@sisk.pl> <200607112245.11462.ncunningham@linuxmail.org> In-Reply-To: <200607112245.11462.ncunningham@linuxmail.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200607112354.56078.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, 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%. Greetings, Rafael