From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752130Ab1IDRSd (ORCPT ); Sun, 4 Sep 2011 13:18:33 -0400 Received: from rcsinet15.oracle.com ([148.87.113.117]:53568 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751085Ab1IDRS0 (ORCPT ); Sun, 4 Sep 2011 13:18:26 -0400 To: "Andi Kleen" Cc: "Martin K. Petersen" , djwong@us.ibm.com, "Greg Freemyer" , "Andreas Dilger" , "Theodore Tso" , "Sunil Mushran" , "Amir Goldstein" , "linux-kernel" , "Mingming Cao" , "Joel Becker" , "linux-fsdevel" , linux-ext4@vger.kernel.org, "Coly Li" Subject: Re: [PATCH v1 00/16] ext4: Add metadata checksumming From: "Martin K. Petersen" Organization: Oracle References: <20110901003030.31048.99467.stgit@elm3c44.beaverton.ibm.com> <20110902182214.GC12086@tux1.beaverton.ibm.com> <6fdb58aed1dae8020900e65cbfb34b28.squirrel@www.firstfloor.org> Date: Sun, 04 Sep 2011 13:17:27 -0400 In-Reply-To: <6fdb58aed1dae8020900e65cbfb34b28.squirrel@www.firstfloor.org> (Andi Kleen's message of "Sun, 4 Sep 2011 18:54:28 +0200") Message-ID: User-Agent: Gnus/5.110017 (No Gnus v0.17) Emacs/23.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Source-IP: rtcsinet21.oracle.com [66.248.204.29] X-CT-RefId: str=0001.0A090203.4E63B2D1.007D,ss=1,re=0.000,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >>>>> "Andi" == Andi Kleen writes: >> On Westmere and beyond it is possible to accelerate generic CRC >> calculation using the PCLMULQDQ operation. There are many of our CRC Andi> Faster than the lookup table? That's hard to believe. Using PCLMULQDQ you can parallelize the calculation. You can even boost hw CRC32C performance that way. http://download.intel.com/design/intarch/papers/323405.pdf http://download.intel.com/design/intarch/papers/323102.pdf -- Martin K. Petersen Oracle Linux Engineering