Received: with ECARTIS (v1.0.0; list netdev); Fri, 13 Jun 2003 16:56:51 -0700 (PDT) Received: from pizda.ninka.net (IDENT:root@pizda.ninka.net [216.101.162.242]) by oss.sgi.com (8.12.9/8.12.9) with SMTP id h5DNuh2x023121 for ; Fri, 13 Jun 2003 16:56:43 -0700 Received: from localhost (IDENT:davem@localhost.localdomain [127.0.0.1]) by pizda.ninka.net (8.9.3/8.9.3) with ESMTP id QAA03410; Fri, 13 Jun 2003 16:52:51 -0700 Date: Fri, 13 Jun 2003 16:52:50 -0700 (PDT) Message-Id: <20030613.165250.41635765.davem@redhat.com> To: scott.feldman@intel.com Cc: anton@samba.org, haveblue@us.ibm.com, hdierks@us.ibm.com, dwg@au1.ibm.com, linux-kernel@vger.kernel.org, milliner@us.ibm.com, ricardoz@us.ibm.com, twichell@us.ibm.com, netdev@oss.sgi.com Subject: Re: e1000 performance hack for ppc64 (Power4) From: "David S. Miller" In-Reply-To: References: X-FalunGong: Information control. X-Mailer: Mew version 2.1 on Emacs 21.1 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-archive-position: 3222 X-ecartis-version: Ecartis v1.0.0 Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com X-original-sender: davem@redhat.com Precedence: bulk X-list: netdev From: "Feldman, Scott" Date: Fri, 13 Jun 2003 16:52:18 -0700 > > Why not instead find out if it's possible to have the e1000 > > fetch the entire cache line where the first byte of the > > packet resides? Even ancient designes like SunHME do that. > > Rusty and I were wondering why the e1000 didnt do that exact thing. > > Scott: is it possible to enable such a thing? I thought the answer was no, so I double checked with a couple of hardware guys, and the answer is still no. Sigh... So Anton, when the PCI controller gets a set of sub-cacheline word reads from the device, it reads the value from memory once for every one of those words? ROFL, if so... I can't believe they wouldn't put caches on the PCI controller for this, at least a one-behind that snoops the bus :(