From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Torvalds Subject: Re: Compression speed for large files Date: Mon, 3 Jul 2006 16:02:39 -0700 (PDT) Message-ID: References: <20060703214503.GA3897@coredump.intra.peff.net> <44A99961.8090504@fys.uio.no> Mime-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Cc: Jeff King , Joachim B Haga , git@vger.kernel.org X-From: git-owner@vger.kernel.org Tue Jul 04 01:05:44 2006 Return-path: Envelope-to: gcvg-git@gmane.org Received: from vger.kernel.org ([209.132.176.167]) by ciao.gmane.org with esmtp (Exim 4.43) id 1FxXRO-00065e-TT for gcvg-git@gmane.org; Tue, 04 Jul 2006 01:02:55 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932287AbWGCXCt (ORCPT ); Mon, 3 Jul 2006 19:02:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932290AbWGCXCt (ORCPT ); Mon, 3 Jul 2006 19:02:49 -0400 Received: from smtp.osdl.org ([65.172.181.4]:43199 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S932287AbWGCXCs (ORCPT ); Mon, 3 Jul 2006 19:02:48 -0400 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 k63N2enW001493 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO); Mon, 3 Jul 2006 16:02:41 -0700 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 k63N2dBb005541; Mon, 3 Jul 2006 16:02:40 -0700 To: Joachim Berdal Haga In-Reply-To: <44A99961.8090504@fys.uio.no> X-Spam-Status: No, hits=0 required=5 tests= X-Spam-Checker-Version: SpamAssassin 2.63-osdl_revision__1.81__ X-MIMEDefang-Filter: osdl$Revision: 1.135 $ X-Scanned-By: MIMEDefang 2.36 Sender: git-owner@vger.kernel.org Precedence: bulk X-Mailing-List: git@vger.kernel.org Archived-At: On Tue, 4 Jul 2006, Joachim Berdal Haga wrote: > > Here's a test with "time gzip -[169] -c file >/dev/null". Random data > from /dev/urandom, kernel headers are concatenation of *.h in kernel > sources. All times in seconds, on my puny home computer (1GHz Via Nehemiah) That "Via Nehemiah" is probably a big part of it. I think the VIA Nehemiah just has a 64kB L2 cache, and I bet performance plummets if the tables end up being used past that. And I think a large part of the higher compressions is that they allow the compression window and tables to grow bigger. Linus