From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Torvalds Subject: Re: Some git performance measurements.. Date: Thu, 29 Nov 2007 09:48:19 -0800 (PST) Message-ID: References: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Git Mailing List To: Nicolas Pitre X-From: git-owner@vger.kernel.org Thu Nov 29 18:50:14 2007 Return-path: Envelope-to: gcvg-git-2@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by lo.gmane.org with esmtp (Exim 4.50) id 1IxnWJ-0003Yb-0M for gcvg-git-2@gmane.org; Thu, 29 Nov 2007 18:49:51 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932128AbXK2RtJ (ORCPT ); Thu, 29 Nov 2007 12:49:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761132AbXK2RtI (ORCPT ); Thu, 29 Nov 2007 12:49:08 -0500 Received: from smtp2.linux-foundation.org ([207.189.120.14]:56376 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760357AbXK2RtG (ORCPT ); Thu, 29 Nov 2007 12:49:06 -0500 Received: from imap1.linux-foundation.org (imap1.linux-foundation.org [207.189.120.55]) by smtp2.linux-foundation.org (8.13.5.20060308/8.13.5/Debian-3ubuntu1.1) with ESMTP id lATHmKwY004443 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Thu, 29 Nov 2007 09:48:21 -0800 Received: from localhost (localhost [127.0.0.1]) by imap1.linux-foundation.org (8.13.5.20060308/8.13.5/Debian-3ubuntu1.1) with ESMTP id lATHmJxf031981; Thu, 29 Nov 2007 09:48:19 -0800 In-Reply-To: X-Spam-Status: No, hits=-2.727 required=5 tests=AWL,BAYES_00 X-Spam-Checker-Version: SpamAssassin 3.1.0-osdl_revision__1.47__ X-MIMEDefang-Filter: lf$Revision: 1.188 $ X-Scanned-By: MIMEDefang 2.53 on 207.189.120.14 Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: On Thu, 29 Nov 2007, Nicolas Pitre wrote: > > Well, see below for the patch that actually split the pack data into > objects of the same type. Doing that "git checkout" on the kernel tree > did improve things for me although not spectacularly. Umm. See my earlier numbers. For "git checkout" with cold cache, the *bulk* of the time is actually the ".gitignore" file lookups, so if you see a three-second improvement out of 17s, it may not look spectacular, but considering that probably 10s of those 17s were something *else* going on, I suspect that if you really did just a plain "git checkout", you actually *do* have a spectacular improvement of roughly 7s -> 4s! Try with time git read-tree -m -u HEAD HEAD > /dev/null instead. But if that is what you already did, then yeah, the performance improvement for cold-cache wasn't as big as I was hoping for. Linus