Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753711AbZDWBg2 (ORCPT ); Wed, 22 Apr 2009 21:36:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751432AbZDWBgR (ORCPT ); Wed, 22 Apr 2009 21:36:17 -0400 Received: from terminus.zytor.com ([198.137.202.10]:38010 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751183AbZDWBgQ (ORCPT ); Wed, 22 Apr 2009 21:36:16 -0400 Message-ID: <49EFC5DD.9090201@zytor.com> Date: Wed, 22 Apr 2009 18:35:25 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Andre Noll CC: Bill Davidsen , Matti Aarnio , Jesper Juhl , Prakash Punnoor , Michael Tokarev , linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, neilb@suse.de Subject: Re: Proposal: make RAID6 code optional References: <200904180946.27722.prakash@punnoor.de> <49E98AD2.8060601@msgid.tls.msk.ru> <200904181117.03418.prakash@punnoor.de> <20090418145850.GD28512@mea-ext.zmailer.org> <49EDD11E.2030309@tmr.com> <49EE00F9.6090000@zytor.com> <20090422180051.GD13280@skl-net.de> <49EF6457.90505@zytor.com> <20090422185703.GF13280@skl-net.de> In-Reply-To: <20090422185703.GF13280@skl-net.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 931 Lines: 24 Andre Noll wrote: > On 11:39, H. Peter Anvin wrote: >> Yes, I believe it would be easier than having dynamically allocated >> arrays. Dynamically generated arrays using static memory allocations >> (bss) is one thing, but that would only reduce size of the module on >> disk, which I don't think anyone considers a problem. > > We would save 64K of RAM in the raid5-only case if we'd defer the > allocation of the multiplication table until the first raid6 array > is about to be started. Yes, and we'd have to access it through a pointer for the rest of eternity. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/