From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261482AbVDJMEF (ORCPT ); Sun, 10 Apr 2005 08:04:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261481AbVDJMEF (ORCPT ); Sun, 10 Apr 2005 08:04:05 -0400 Received: from mx1.elte.hu ([157.181.1.137]:12005 "EHLO mx1.elte.hu") by vger.kernel.org with ESMTP id S261482AbVDJMEA (ORCPT ); Sun, 10 Apr 2005 08:04:00 -0400 Date: Sun, 10 Apr 2005 14:03:31 +0200 From: Ingo Molnar To: Paul Jackson Cc: Chris Wedgwood , torvalds@osdl.org, davem@davemloft.net, andrea@suse.de, mbp@sourcefrog.net, linux-kernel@vger.kernel.org, dlang@digitalinsight.com Subject: Re: Kernel SCM saga.. Message-ID: <20050410120331.GA8878@elte.hu> References: <1112939769.29544.161.camel@hope> <20050408083839.GC3957@opteron.random> <20050409022701.GA14085@opteron.random> <20050409155511.7432d5c7.davem@davemloft.net> <20050410001435.GA23401@taniwha.stupidest.org> <20050409185636.0945abdf.pj@engr.sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050409185636.0945abdf.pj@engr.sgi.com> User-Agent: Mutt/1.4.2.1i X-ELTE-SpamVersion: MailScanner 4.31.6-itk1 (ELTE 1.2) SpamAssassin 2.63 ClamAV 0.73 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Paul Jackson wrote: > These 16817 files consume: > > 224 MBytes uncompressed and > 95 MBytes compressed > > (using zlib's minigzip, on a 4 KB page reiserfs.) that's a 42.4% compressed size. Using a (much) more CPU-intense compression method (bzip -9), the compressed size is down to 45 MBytes. (a ratio of 20.2%) using default 'gzip' i get 57 MB compressed. > Since each change will get its own copy of the file, multiplying these > two sizes (224 and 95) by 12.2 changes per file means the disk cost > would be: > > 2.73 GByte uncompressed, or > 1.16 GBytes compressed. with bzip2 -9 it would be 551 MBytes. It might as well be practical on faster CPUs, a full tree (224 MBytes, 45 MBytes compressed) decompresses in 24 seconds on a 3.4GHz P4 - single CPU. (and with dual core likely becoming the standard, we might as well divide that by two) With default gzip it's 3.3 seconds though, and that still compresses it down to 57 MB. Ingo