From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Receive steering and hash and cache misses Date: Fri, 2 Apr 2010 10:26:50 -0700 Message-ID: <20100402102650.5bdb5b52@nehalam> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Eric Dumazet Return-path: Received: from mail.vyatta.com ([76.74.103.46]:43013 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755789Ab0DBR1M (ORCPT ); Fri, 2 Apr 2010 13:27:12 -0400 Sender: netdev-owner@vger.kernel.org List-ID: Although Receive Packet Steering can use a hardware generated receive hash the device driver still causes an unnecessary cache miss on the interrupt processing CPU. The current Ethernet network device driver receive processing has the device driver calling eth_type_trans() which causes a the interrupt CPU to read the received frame header. Is there some way the hardware receive hash value could be used to steer to the receive CPU, then have the receive CPU find the Ethernet type field (eth_type_trans)?