From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.176.0/21 X-Spam-Status: No, score=-3.5 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MSGID_FROM_MTA_HEADER,RP_MATCHES_RCVD shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 From: Linus Torvalds Subject: Re: [PATCH] change the unpack limit treshold to a saner value Date: Wed, 6 Dec 2006 17:08:12 -0800 (PST) Message-ID: References: Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII NNTP-Posting-Date: Thu, 7 Dec 2006 01:08:33 +0000 (UTC) Cc: Junio C Hamano , git@vger.kernel.org Return-path: Envelope-to: gcvg-git@gmane.org In-Reply-To: X-MIMEDefang-Filter: osdl$Revision: 1.162 $ X-Scanned-By: MIMEDefang 2.36 Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: Received: from vger.kernel.org ([209.132.176.167]) by dough.gmane.org with esmtp (Exim 4.50) id 1Gs7kV-0006Br-0t for gcvg-git@gmane.org; Thu, 07 Dec 2006 02:08:31 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S937849AbWLGBI2 (ORCPT ); Wed, 6 Dec 2006 20:08:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S937901AbWLGBI2 (ORCPT ); Wed, 6 Dec 2006 20:08:28 -0500 Received: from smtp.osdl.org ([65.172.181.25]:32963 "EHLO smtp.osdl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S937849AbWLGBI1 (ORCPT ); Wed, 6 Dec 2006 20:08:27 -0500 Received: from shell0.pdx.osdl.net (fw.osdl.org [65.172.181.6]) by smtp.osdl.org (8.12.8/8.12.8) with ESMTP id kB718DID014183 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO); Wed, 6 Dec 2006 17:08:14 -0800 Received: from localhost (shell0.pdx.osdl.net [10.9.0.31]) by shell0.pdx.osdl.net (8.13.1/8.11.6) with ESMTP id kB718Cq8023758; Wed, 6 Dec 2006 17:08:13 -0800 To: Nicolas Pitre Sender: git-owner@vger.kernel.org On Wed, 6 Dec 2006, Nicolas Pitre wrote: > > This is why I think the current default treshold should be 3 instead of > the insane value of 5000. But since it feels a bit odd to go from 5000 > to 3 I setled on 10. Definitely not. We have a much easier time handling many loose packed objects than many pack-files. For many reasons, but two really obvious ones: - pack-file indexes get read in on startup, and we maintain an explicit list of them. Having lots of pack-files adds overhead that doesn't exist for lots of loose objects. - loose files are spread out over 256 subdirectories to make lookup easier, packfiles are not (and always create an index file too). So in general, as a trivial heuristic, you probably want about 512 times as many loose objects as you want pack-files, i fonly because of the latter issue, because you can much more easily handle lots of loose objects than lots of pack-files. So it's _not_ a factor of 3. Or even 10. But since there _is_ reason to do pack-files too, and since using too big a value means that you never end up keeping a pack-file _at_all_ if you pull often, I'd suggest that rather than use a limit of 512 you go for something like 100-200 objects as the threshold (of course, the proper one would depend on the distribution of the size of your pack-files, but I'll just hand-wave and say that together with occasional re-packing, something in that range is _generally_ going to be a good idea).