From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932253AbWBULeO (ORCPT ); Tue, 21 Feb 2006 06:34:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932686AbWBULeO (ORCPT ); Tue, 21 Feb 2006 06:34:14 -0500 Received: from gprs189-60.eurotel.cz ([160.218.189.60]:31980 "EHLO amd.ucw.cz") by vger.kernel.org with ESMTP id S932253AbWBULeO (ORCPT ); Tue, 21 Feb 2006 06:34:14 -0500 Date: Tue, 21 Feb 2006 12:33:37 +0100 From: Pavel Machek To: Andy Lutomirski Cc: Matthias Hensler , kernel list , Nigel Cunningham , Sebastian Kgler , rjw@sisk.pl Subject: Re: Which is simpler? (Was Re: [Suspend2-devel] Re: [ 00/10] [Suspend2] Modules support.) Message-ID: <20060221113337.GP21557@elf.ucw.cz> References: <20060201113710.6320.68289.stgit@localhost.localdomain> <200602200709.17955.nigel@suspend2.net> <20060219212952.GI15311@elf.ucw.cz> <200602201025.01823.nigel@suspend2.net> <20060220005333.GL15608@elf.ucw.cz> <20060220094728.GD19293@kobayashi-maru.wspse.de> <43FA97D9.4070902@myrealbox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <43FA97D9.4070902@myrealbox.com> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Po 20-02-06 20:32:25, Andy Lutomirski wrote: > Matthias Hensler wrote: > >Hi. > > > >On Mon, Feb 20, 2006 at 01:53:33AM +0100, Pavel Machek wrote: > > > >>Only feature I can't do is "save whole pagecache"... and 14000 lines > >>of code for _that_ is a bit too much. I could probably patch my kernel > >>to dump pagecache to userspace, but I do not think it is worth the > >>effort. > > > > > >I do not think that Suspend 2 needs 14000 lines for that, the core is > >much smaller. But besides, _not_ saving the pagecache is a really _bad_ > >idea. I expect to have my system back after resume, in the same state I > >had left it prior to suspend. I really do not like it how it is done by > >Windows, it is just ugly to have a slowly responding system after > >resume, because all caches and buffers are gone. > > > >I can only speak for myself, but I want to work with my system from the > >moment my desktop is back. > > I Am Not A VM Hacker, but: > > What's the point of saving pagecache during suspend? This seems like a > total waste. Why don't we save a list of pages in pagecache to disk, > then, after resume, prefetch them all back in. This will slow down > resume (extra seeks, minimized if we sort the list, and inability > to compress these pages), but it will speed up suspend, and it sounds > a lot simpler. There's already a patch to add swap prefetching, and > this can't be much more complicated. I'd actually love to see this implemented. It would be useful for suspend-to-disk (obviously), but also for benchmarks. > While I'm at it, here's another pie-in-the-sky idea. If we had the Yes, that's quite far in the sky :-). Pavel -- Web maintainer for suspend.sf.net (www.sf.net/projects/suspend) wanted...