Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262329AbUCMHru (ORCPT ); Sat, 13 Mar 2004 02:47:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262416AbUCMHru (ORCPT ); Sat, 13 Mar 2004 02:47:50 -0500 Received: from [64.62.253.241] ([64.62.253.241]:64785 "EHLO staidm.org") by vger.kernel.org with ESMTP id S262329AbUCMHrt (ORCPT ); Sat, 13 Mar 2004 02:47:49 -0500 Date: Fri, 12 Mar 2004 23:49:35 -0800 From: Bryan Rittmeyer To: Benjamin Herrenschmidt Cc: Linux Kernel list , linuxppc-dev list , Paul Mackerras Subject: Re: [PATCH] ppc32 copy_to_user dcbt fixup Message-ID: <20040313074934.GA15019@staidm.org> References: <20040313041547.GB11512@staidm.org> <1079153403.2348.82.camel@gaston> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1079153403.2348.82.camel@gaston> User-Agent: Mutt/1.3.28i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 703 Lines: 18 On Sat, Mar 13, 2004 at 03:50:03PM +1100, Benjamin Herrenschmidt wrote: > It would be wise to make the dcbz as long as possible in "advance" > before the actual write to the cache line. I guess we could try "pre-dcbz" ala the dcbt prefetch code. Even dcbz right before stw is probably cheaper than RAM loading data that will be totally overwritten. It's hard to lose eliminating bus I/O (especially reads). Any comments on the dcbt prefetch patch? -Bryan - 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/