From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: Yet another base64 patch Date: Wed, 13 Apr 2005 22:36:52 -0700 Message-ID: <425E0174.4080404@zytor.com> References: <425DEF64.60108@zytor.com> <20050414022413.GB18655@64m.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: git@vger.kernel.org X-From: git-owner@vger.kernel.org Thu Apr 14 07:36:49 2005 Return-path: Received: from vger.kernel.org ([12.107.209.244]) by ciao.gmane.org with esmtp (Exim 4.43) id 1DLx1l-0001BZ-Tw for gcvg-git@gmane.org; Thu, 14 Apr 2005 07:36:34 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261429AbVDNFju (ORCPT ); Thu, 14 Apr 2005 01:39:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261432AbVDNFju (ORCPT ); Thu, 14 Apr 2005 01:39:50 -0400 Received: from terminus.zytor.com ([209.128.68.124]:35043 "EHLO terminus.zytor.com") by vger.kernel.org with ESMTP id S261429AbVDNFje (ORCPT ); Thu, 14 Apr 2005 01:39:34 -0400 Received: from [172.27.0.18] (c-67-169-23-106.hsd1.ca.comcast.net [67.169.23.106]) (authenticated bits=0) by terminus.zytor.com (8.13.1/8.13.1) with ESMTP id j3E5aq56029141 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Wed, 13 Apr 2005 22:36:54 -0700 User-Agent: Mozilla Thunderbird 1.0.2-1.3.2 (X11/20050324) X-Accept-Language: en-us, en To: Christopher Li In-Reply-To: <20050414022413.GB18655@64m.dyndns.org> X-Spam-Status: No, score=-5.9 required=5.0 tests=ALL_TRUSTED,BAYES_00 autolearn=ham version=3.0.2 X-Spam-Checker-Version: SpamAssassin 3.0.2 (2004-11-16) on terminus.zytor.com Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Christopher Li wrote: > On Wed, Apr 13, 2005 at 09:19:48PM -0700, H. Peter Anvin wrote: > >>Checking out the total kernel tree (time checkout-cache -a into an empty >>directory): >> >> Cache cold Cache hot >>stock 3:46.95 19.95 >>base64 5:56.20 23.74 >>flat 2:44.13 15.68 > >>It seems that the flat format, at least on ext3 with dircache, is >>actually a major performance win, and that the second level loses quite >>a bit. > > That is not surprising due to the directory index in ext3. Htree is pretty > good at random access and the hashed file name distribute evenly, that is > the best case for htree. > Right, so by not trying to do the filesystem's job for it we actually come out ahead. -hpa