From mboxrd@z Thu Jan 1 00:00:00 1970 From: jamal Subject: Re: Network card IRQ balancing with Intel 5000 series chipsets Date: Wed, 27 Dec 2006 09:31:19 -0500 Message-ID: <1167229879.3807.24.camel@localhost> References: <7e63f56c0612240134s452f6510h8483fb31e5efe799@mail.gmail.com> <1167039303.3281.1574.camel@laptopd505.fenrus.org> <7e63f56c0612250326td172f28n532435b23d18b69f@mail.gmail.com> <1167046499.3281.1623.camel@laptopd505.fenrus.org> <7e63f56c0612250454g5520bd6aja0fb9ab2656ff74e@mail.gmail.com> <1167158658.3746.12.camel@localhost> <1167170793.3281.3209.camel@laptopd505.fenrus.org> <1167173199.3746.45.camel@localhost> <1167179309.3281.3342.camel@laptopd505.fenrus.org> <1167191279.3746.60.camel@localhost> <7e63f56c0612262309p5337a753q3b1748910fce70b5@mail.gmail.com> Reply-To: hadi@cyberus.ca Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Arjan van de Ven , netdev@vger.kernel.org Return-path: Received: from wx-out-0506.google.com ([66.249.82.228]:39607 "EHLO wx-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932944AbWL0ObX (ORCPT ); Wed, 27 Dec 2006 09:31:23 -0500 Received: by wx-out-0506.google.com with SMTP id h27so4235085wxd for ; Wed, 27 Dec 2006 06:31:23 -0800 (PST) To: Robert Iakobashvili In-Reply-To: <7e63f56c0612262309p5337a753q3b1748910fce70b5@mail.gmail.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wed, 2006-27-12 at 09:09 +0200, Robert Iakobashvili wrote: > > My scenario is treatment of RTP packets in kernel space with a single network > card (both Rx and Tx). The default of the Intel 5000 series chipset is > affinity of each > network card to a certain CPU. Currently, neither with irqbalance nor > with kernel > irq-balancing (MSI and io-apic attempted) I do not find a way to > balance that irq. In the near future, when the NIC vendors wake up[1] because CPU vendors - including big bad Intel - are going to be putting out a large number of hardware threads, you should be able to do more clever things with such a setup. At the moment, just tie it to a single CPU and have your other processes that are related running/bound on the other cores so you can utilize them. OTOH, you say you are only using 30% of the one CPU, so it may not be a big deal to tie your single nic to on cpu. cheers, jamal [1] If you are able to change the NIC in your setup try looking at netiron; email Leonid.Grossman@netiron.com they have a much clever nic than the e1000. It has multiple DMA receive rings which are selectable via a little classifier (example you could have RTP going to CPU0 and rest going to CPU1). The DMA rings could be tied to different interupts/MSI and with some little work could be made to appear like several interfaces.