From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 23 May 2002 12:37:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 23 May 2002 12:37:19 -0400 Received: from pizda.ninka.net ([216.101.162.242]:47329 "EHLO pizda.ninka.net") by vger.kernel.org with ESMTP id ; Thu, 23 May 2002 12:37:17 -0400 Date: Thu, 23 May 2002 09:21:55 -0700 (PDT) Message-Id: <20020523.092155.70675460.davem@redhat.com> To: davidm@hpl.hp.com, davidm@napali.hpl.hp.com Cc: hugh@veritas.com, linux-kernel@vger.kernel.org, andrea@suse.de, torvalds@transmeta.com Subject: Re: Q: PREFETCH_STRIDE/16 From: "David S. Miller" In-Reply-To: <15597.6222.724619.443491@napali.hpl.hp.com> X-Mailer: Mew version 2.1 on Emacs 21.1 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org From: David Mosberger Date: Thu, 23 May 2002 09:26:54 -0700 That code certainly wasn't optimized for ia64. Furthermore, I also do not like the prefetch distance it's using. In fact, in my ia64-patch, I use the following code instead: prefetchw(pmd + j + PREFETCH_STRIDE/sizeof(*pmd)); This is more sensible (because it really does prefetch by the PREFETCH_STRIDE distance) and it also happens to run (slightly) faster on Itanium. All of these particular prefetches are amusing, with or without your fix, considering there are other more powerful ways to optimize this stuff. :-)