From: "Darrick J. Wong" Subject: Re: [PATCH 3/3] crc32c: Implement a self-test for CRC32c Date: Thu, 1 Sep 2011 15:28:14 -0700 Message-ID: <20110901222814.GB12086@tux1.beaverton.ibm.com> References: <20110901003317.32645.16843.stgit@elm3c44.beaverton.ibm.com> <20110901003336.32645.32746.stgit@elm3c44.beaverton.ibm.com> <03ac01cc6869$9cd23b60$d676b220$@systemfabricworks.com> <20110901221854.GA12086@tux1.beaverton.ibm.com> <20110901222422.GA5771@infradead.org> Reply-To: djwong@us.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Bob Pearson , "'Andreas Dilger'" , "'Herbert Xu'" , "'Theodore Tso'" , "'David Miller'" , "'linux-kernel'" , "'Mingming Cao'" , "'linux-crypto'" , "'linux-fsdevel'" , linux-ext4@vger.kernel.org To: Christoph Hellwig Return-path: Received: from e9.ny.us.ibm.com ([32.97.182.139]:60894 "EHLO e9.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932160Ab1IAW2U (ORCPT ); Thu, 1 Sep 2011 18:28:20 -0400 Content-Disposition: inline In-Reply-To: <20110901222422.GA5771@infradead.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Thu, Sep 01, 2011 at 06:24:22PM -0400, Christoph Hellwig wrote: > On Thu, Sep 01, 2011 at 03:18:54PM -0700, Darrick J. Wong wrote: > > I suspect it would be pretty easy to adapt the Makefile to generate the > > relevant .c and .h files; in particular it could be useful to use the crypto > > framework for crc32 on the off chance anyone wants to provide hwaccel for that > > too. > > crc32 or crc32c? Note that there already is a hardware optimized crc32c > for recent Intel CPUs in arch/x86/crypto/crc32c-intel.c. crc32, since it currently doesn't use the crypto api at all, and Bob was interested in implementing slice-by-8 for it. Though I suppose so long as there aren't any reasons to override the sw crc32 implementation we could just fall back to Bob's earlier patch to implement slice-by-8 for crc32? I don't mind implementing faster crc32/crc32c. (As far as crc32c goes, my motivation is to make sw crc32c faster for the cases where you don't have Intel hw.) --D