From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: Get rxhash fixes and RFS support in tun Date: Wed, 20 Nov 2013 21:23:21 -0500 (EST) Message-ID: <20131120.212321.700376819925646003.davem@davemloft.net> References: <20131120.190252.940036939480739452.davem@davemloft.net> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, edumazet@google.com, hkchu@google.com To: therbert@google.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:38486 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754336Ab3KUCXY (ORCPT ); Wed, 20 Nov 2013 21:23:24 -0500 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: From: Tom Herbert Date: Wed, 20 Nov 2013 17:09:01 -0800 > I think the sw_rxhash holds more useful information. In > skb_get_rxhash() either we have an L4 hash or we try to get one by > doing the SW computation, this means we don't ever return a HW hash > which is not L4 so basically that case is treated as an invalid hash. > So after a call to skb_get_rxhash, at least one of l4_rxhash or > sw_rxhash is and we won't redo flow dissection on subsequent calls > unless the rxhash is cleared. Ok.... one interesting issue remains, which is that the SW flow dissector considers decapsulating protocols like AH and ESP as "L4". I think we'll need to do something about that at some point.