From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [net-next-2.6 PATCH 2/3] ixgbe: Set MSI-X vectors to NOBALANCING and set affinity Date: Fri, 23 Oct 2009 06:45:52 +0900 Message-ID: <20091023064552.6ca3cbd8@s6510> References: <20091021022713.32449.54868.stgit@localhost.localdomain> <20091021.215031.57955781.davem@davemloft.net> <1256199756.2634.65.camel@ppwaskie-mobl2> <20091022.035601.193700201.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: peter.p.waskiewicz.jr@intel.com, jeffrey.t.kirsher@intel.com, gospo@redhat.com, netdev@vger.kernel.org To: David Miller Return-path: Received: from mail.vyatta.com ([76.74.103.46]:54863 "EHLO mail.vyatta.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755956AbZJVVp4 (ORCPT ); Thu, 22 Oct 2009 17:45:56 -0400 In-Reply-To: <20091022.035601.193700201.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, 22 Oct 2009 03:56:01 -0700 (PDT) David Miller wrote: > From: Peter P Waskiewicz Jr > Date: Thu, 22 Oct 2009 01:22:36 -0700 > > > The first thing any performance guide says is to disable irqbalance > > Such guides are wrong, and that's the end of this discussion. > > These kinds of guides also say to do all kinds of crazy things with > the socket sysctl settings. That's wrong too and we absolutely do not > do things to accomodate nor support those guide suggestions. > > And we won't do that here. > > I'm especially not going to succumb in this case because Arjan has > been more than responsive to making sure irqbalanced in userspace does > the right thing for networking devices, even multiqueue ones. > > So we can make it do the right thing when flow director is present. > In fact, the thing you want for flow director makes sense in the > general case too. irqbalance daemon already has IRQBALANCE_BANNED_INTERRUPTS to work around this. It also has code to special case devices, if you think ixgbe needs special treatment, why not do it there.