Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758748Ab1F1P1W (ORCPT ); Tue, 28 Jun 2011 11:27:22 -0400 Received: from mga14.intel.com ([143.182.124.37]:59253 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757698Ab1F1PZV convert rfc822-to-8bit (ORCPT ); Tue, 28 Jun 2011 11:25:21 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.65,437,1304319600"; d="scan'208";a="19784162" From: "Ma, Ling" To: Ingo Molnar , Andi Kleen CC: "hpa@zytor.com" , "tglx@linutronix.de" , "linux-kernel@vger.kernel.org" Date: Tue, 28 Jun 2011 23:23:52 +0800 Subject: RE: [PATCH RFC] [x86] Optimize copy-page by reducing impact from HW prefetch Thread-Topic: [PATCH RFC] [x86] Optimize copy-page by reducing impact from HW prefetch Thread-Index: Acwxc9zXuTo3YQvYQpKzil1gi1OinwEGCmlA Message-ID: References: <1308351117-32452-1-git-send-email-ling.ma@intel.com> <20110623070448.GA25707@elte.hu> In-Reply-To: <20110623070448.GA25707@elte.hu> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 736 Lines: 19 Hi Ingo > Ling, mind double checking which one is the faster/better one on SNB, > in cold-cache and hot-cache situations, copy_page or copy_page_c? Copy_page_c on hot-cache copy_page_c on SNB combines data to 128bit (processor limit 128bit/cycle for write) after startup latency so it is faster than copy_page which provides 64bit/cycle for write. on cold-cache copy_page_c doesn't use prefetch, which uses prfetch according to copy size, so copy_page function is better. Thanks Ling -- 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/