From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758817Ab1FVUHa (ORCPT ); Wed, 22 Jun 2011 16:07:30 -0400 Received: from mga09.intel.com ([134.134.136.24]:49470 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758540Ab1FVUH3 (ORCPT ); Wed, 22 Jun 2011 16:07:29 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.65,407,1304319600"; d="scan'208";a="16994225" From: Andi Kleen To: ling.ma@intel.com Cc: mingo@elte.hu, hpa@zytor.com, tglx@linutronix.de, linux-kernel@vger.kernel.org Subject: Re: [PATCH RFC] [x86] Optimize copy-page by reducing impact from HW prefetch References: <1308351117-32452-1-git-send-email-ling.ma@intel.com> Date: Wed, 22 Jun 2011 13:05:41 -0700 In-Reply-To: <1308351117-32452-1-git-send-email-ling.ma@intel.com> (ling ma's message of "Sat, 18 Jun 2011 06:51:57 +0800") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ling.ma@intel.com writes: > impact(DCU prefetcher), and simplify original code. > The performance is improved about 15% on core2, 36% on snb respectively. > (We use our micro-benchmark, and will do further test according to your requirment) This doesn't make a lot of sense because neither Core-2 nor SNB use the code path you patched. They all use the rep ; movs path -Andi -- ak@linux.intel.com -- Speaking for myself only