From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andi Kleen Subject: Re: small RPS cache for fragments? Date: Tue, 17 May 2011 15:06:04 -0700 Message-ID: References: <20110517.143342.1566027350038182221.davem@davemloft.net> <20110517.174431.1004332995189918916.davem@davemloft.net> <20110517.175044.2057517197524794568.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org To: David Miller Return-path: Received: from mga11.intel.com ([192.55.52.93]:1887 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932389Ab1EQWGh (ORCPT ); Tue, 17 May 2011 18:06:37 -0400 In-Reply-To: <20110517.175044.2057517197524794568.davem@davemloft.net> (David Miller's message of "Tue, 17 May 2011 17:50:44 -0400 (EDT)") Sender: netdev-owner@vger.kernel.org List-ID: David Miller writes: > > We're discussing the idea to do the defragmentation first > so we can choose the flow properly and steer the packet > to the correct cpu. > > This also would allos each fragmented packet to traverse the > stack only once (one route lookup etc.) instead of once per > fragment. You could always check first in a cheap way (e.g. a small hash table) if it's local or not (and bypass the defragmentation if routing is turned off or the hash table would have collisions) On the other hand if fragmentation is expensive it's probably better to do it later anyways to spread it out better. -Andi -- ak@linux.intel.com -- Speaking for myself only