From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [net-next-2.6 PATCH] x86: Drop CONFIG_MCORE2 check around setting of NET_IP_ALIGN Date: Thu, 1 Jul 2010 17:26:54 -0700 Message-ID: <20100701172654.713b6043@nehalam> References: <20100701232742.15934.49030.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net, netdev@vger.kernel.org, gospo@redhat.com, bphilips@novell.com, Andi Kleen , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Alexander Duyck To: Jeff Kirsher Return-path: Received: from mail.vyatta.com ([76.74.103.46]:54833 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750965Ab0GBA06 (ORCPT ); Thu, 1 Jul 2010 20:26:58 -0400 In-Reply-To: <20100701232742.15934.49030.stgit@localhost.localdomain> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 01 Jul 2010 16:28:27 -0700 Jeff Kirsher wrote: > From: Alexander Duyck > > This patch removes the CONFIG_MCORE2 check from around NET_IP_ALIGN. It is > based on a suggestion from Andi Kleen. The assumption is that there are > not any x86 cores where unaligned access is really slow, and this change > would allow for a performance improvement to still exist on configurations > that are not necessarily optimized for Core 2. > > Cc: Andi Kleen > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: "H. Peter Anvin" > Cc: x86@kernel.org > Signed-off-by: Alexander Duyck > Signed-off-by: Jeff Kirsher > --- This is a good idea, but warnig it may end up masking broken hardware. Developers of new drivers will end up never exercising unaligned DMA, resulting in hardware that doesn't work on platforms that have NET_IP_ALIGN set to 2. --