From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752199AbWFXLIo (ORCPT ); Sat, 24 Jun 2006 07:08:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752203AbWFXLIo (ORCPT ); Sat, 24 Jun 2006 07:08:44 -0400 Received: from ns.virtualhost.dk ([195.184.98.160]:49433 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S1751559AbWFXLIn (ORCPT ); Sat, 24 Jun 2006 07:08:43 -0400 Date: Sat, 24 Jun 2006 13:10:00 +0200 From: Jens Axboe To: James Cc: linux-kernel@vger.kernel.org, ck@vds.kolivas.org Subject: Re: [PATCH] fcache: a remapping boot cache Message-ID: <20060624110959.GQ4083@suse.de> References: <20060515091806.GA4110@suse.de> <20060515101019.GA4068@suse.de> <20060516074628.GA16317@suse.de> <4d8e3fd30605301438k457f6242x1df64df9bab7f8f1@mail.gmail.com> <20060531061234.GC29535@suse.de> <1e1a7e1b0606232044x11136be5p332716b757ecd537@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1e1a7e1b0606232044x11136be5p332716b757ecd537@mail.gmail.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Jun 24 2006, James wrote: > Set this up on my laptop yesterday with some awesome results. I'm > using 2.6.17-ck1 which has v2.1. > > Heres some bootcharts, before, after, and a prime run. > > http://archlinux.org/~james/normal.png > http://archlinux.org/~james/fs-fcache.png > http://archlinux.org/~james/fs-fcache-prime.png > > Repeated boots show about the same 6 second improvement, 32 down to 26 > seconds. Looking at the slowdowns in the fs-fcache run, most are due > to cpu load, waiting on network or, modprobe, and not disk access. X > now starts nearly instantaneously. > > As an experiment, I primed my cache right through to logging into my > desktop environment. It was so effective, that now when I login, the > GNOME splash screen only flickers onto the screen briefly, and the > panels appear almost instantly. This is a big improvment over without > fcache, where you'd see each component of GNOME being loaded on the > splash screen, nautilus, metacity, and the panels would take quite a > bit of time to render and load all their applets. > > Impressive work, I hope to see it broadened to other filesystems, > improved and merged to vanilla soon because it has clear improvements. Thanks for giving it a spin! I have plans to implement some improvements on monday that will speed it up even more, I hope I can talk you into retesting it then. Basically it make sure we always get full speed out of the drive by extending the 4kb reads with a sliding window cache. That will help both drive efficiency, and also speed up the cases where sub sequent boots differ just a little bit from the primed boot (often the case with parallel init scripts). It should win you a few seconds more in total, would be my guess. I hope to be able to extend it to xfs and reiser in the very near future as well, should not be hard to do. -- Jens Axboe