From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753417AbZHOLAb (ORCPT ); Sat, 15 Aug 2009 07:00:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753282AbZHOLAa (ORCPT ); Sat, 15 Aug 2009 07:00:30 -0400 Received: from mailhost18.gawab.com ([66.220.20.18]:59113 "HELO info3.gawab.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753218AbZHOLAa (ORCPT ); Sat, 15 Aug 2009 07:00:30 -0400 X-Trusted: Whitelisted From: Al Boldi To: ngupta@vflare.org Subject: Re: compcache as a pre-swap area Date: Sat, 15 Aug 2009 14:00:52 +0300 User-Agent: KMail/1.5 Cc: Hugh Dickins , Matthew Wilcox , Ingo Molnar , Peter Zijlstra , linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <200908122007.43522.ngupta@vflare.org> <4A84EDE4.1080605@vflare.org> <200908141849.19797.a1426z@gawab.com> In-Reply-To: <200908141849.19797.a1426z@gawab.com> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200908151400.52554.a1426z@gawab.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Al Boldi wrote: > Nitin Gupta wrote: > > On 08/14/2009 09:32 AM, Al Boldi wrote: > > > So once compcache fills up, it will start to age its contents into > > > normal swap? > > > > This is desirable but not yet implemented. For now, if 'backing swap' is > > used, compcache will forward incompressible pages to the backing swap > > device. If compcache fills up, kernel will simply send further swap-outs > > to swap device which comes next in priority. > > Ok, this sounds acceptable for now. > > The important thing now is to improve performance to a level comparable to > a system with normal ssd-swap. Do you have such a comparisson? > > Another interresting benchmark would be to use compcache in a maximized > configuration, ie. on a system w/ 1024KB Ram assign 960KB for compcache and > leave 64KB for the system, and then see how it performs. This may easily > pinpoint any bottlenecks compcache has, if any. I am wondering, is it possible to run a system in 64KB? Ok, make that MB instead. Thanks! -- Al