From mboxrd@z Thu Jan 1 00:00:00 1970 From: Changli Gao Subject: Re: [PATCH] RPS: support 802.1q and pppoe session Date: Thu, 25 Mar 2010 13:12:57 +0800 Message-ID: <412e6f7f1003242212t242a30e0k635bdfb861c324e4@mail.gmail.com> References: <4BAAE6E9.6030103@gmail.com> <1269493402.15280.29.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "David S. Miller" , Tom Herbert , netdev@vger.kernel.org To: Eric Dumazet Return-path: Received: from mail-iw0-f176.google.com ([209.85.223.176]:54111 "EHLO mail-iw0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752264Ab0CYFNS convert rfc822-to-8bit (ORCPT ); Thu, 25 Mar 2010 01:13:18 -0400 Received: by iwn6 with SMTP id 6so3348509iwn.4 for ; Wed, 24 Mar 2010 22:13:17 -0700 (PDT) In-Reply-To: <1269493402.15280.29.camel@edumazet-laptop> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Mar 25, 2010 at 1:03 PM, Eric Dumazet = wrote: > > While this might sounds a good idea, you really should split this in = two > parts. > > By the way, why not handling IPIP too ? I'm not sure if it is a good idea to support VLAN and PPPOE, and actually David don't like it. :( > > Because I believe 802.1q part has no added value for instance, since > packet handled by CPUX will be decoded and passed to VLAN device, hav= ing > a chance to be fully taken by RPS, since we go back to netif_rx(). > > Probably same thing for IPIP / PPPOE can be discussed. It is useful when Linux is run as a bridge. > > I agree we might need a flag or something to reset rxhash to 0 somewh= ere > (probably in non accelerated vlan rx handling) to force second > get_rps_cpu() invocation to recompute it. This small correction has n= o > cost if put outside of get_rps_cpus(). > > If get_rps_cpus() is too complex, it might become too slow for typica= l > use. We should find smart ways to solve your performance problem if t= hey > ever exist. > It means that more than one IPI will be sent for just a single packets, I don't think the cost is acceptable. --=20 Regards=EF=BC=8C Changli Gao(xiaosuo@gmail.com)