Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752866AbcKCAtq (ORCPT ); Wed, 2 Nov 2016 20:49:46 -0400 Received: from helcar.hengli.com.au ([209.40.204.226]:37843 "EHLO helcar.hengli.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751314AbcKCAtp (ORCPT ); Wed, 2 Nov 2016 20:49:45 -0400 Date: Thu, 3 Nov 2016 08:49:34 +0800 From: Herbert Xu To: "Jason A. Donenfeld" Cc: "David S. Miller" , linux-crypto@vger.kernel.org, LKML , Martin Willi Subject: Re: [PATCH] poly1305: generic C can be faster on chips with slow unaligned access Message-ID: <20161103004934.GA30775@gondor.apana.org.au> References: <20161102175810.18647-1-Jason@zx2c4.com> <20161102200959.GA23297@gondor.apana.org.au> <20161102210802.GA26741@gondor.apana.org.au> <20161102212657.GA26887@gondor.apana.org.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 575 Lines: 15 On Wed, Nov 02, 2016 at 11:00:00PM +0100, Jason A. Donenfeld wrote: > > Just tested. I get a 6% slowdown on my Skylake. No good. I think it's > probably best to have the two paths in there, and not reduce it to > one. FWIW I'd rather live with a 6% slowdown than having two different code paths in the generic code. Anyone who cares about 6% would be much better off writing an assembly version of the code. Cheers, -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt