From: Linus Torvalds Subject: Re: How git affects kernel.org performance Date: Tue, 9 Jan 2007 08:23:32 -0800 (PST) Message-ID: References: <1166304080.13548.8.camel@nigel.suspend2.net> <459152B1.9040106@zytor.com> <1168140954.2153.1.camel@nigel.suspend2.net> <45A08269.4050504@zytor.com> <45A083F2.5000000@zytor.com> <20070107085526.GR24090@1wt.eu> <20070107011542.3496bc76.akpm@osdl.org> <20070108030555.GA7289@in.ibm.com> <20070108125819.GA32756@thunk.org> <368329554.17014@ustc.edu.cn> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Theodore Tso , Suparna Bhattacharya , Andrew Morton , Willy Tarreau , "H. Peter Anvin" , git@vger.kernel.org, nigel@nigel.suspend2.net, "J.H." , Randy Dunlap , Pavel Machek , kernel list , webmaster@kernel.org, "linux-ext4@vger.kernel.org" Return-path: Received: from smtp.osdl.org ([65.172.181.24]:51343 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932204AbXAIQ2Q (ORCPT ); Tue, 9 Jan 2007 11:28:16 -0500 To: Fengguang Wu In-Reply-To: <368329554.17014@ustc.edu.cn> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Tue, 9 Jan 2007, Fengguang Wu wrote: > > > > The fastest and probably most important thing to add is some readahead > > smarts to directories --- both to the htree and non-htree cases. If > > Here's is a quick hack to practice the directory readahead idea. > Comments are welcome, it's a freshman's work :) Well, I'd probably have done it differently, but more important is whether this actually makes a difference performance-wise. Have you benchmarked it at all? Doing an echo 3 > /proc/sys/vm/drop_caches is your friend for testing things like this, to force cold-cache behaviour.. Linus