From mboxrd@z Thu Jan 1 00:00:00 1970 From: Don Porter Subject: Re: e1000 softirq load balancing Date: Tue, 14 Oct 2008 18:46:11 -0500 Message-ID: <48F52F43.9040201@cs.utexas.edu> References: <48F4ED7E.4070308@cs.utexas.edu> <20081014.125156.92616351.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-net@vger.kernel.org, netdev@vger.kernel.org To: David Miller Return-path: In-Reply-To: <20081014.125156.92616351.davem@davemloft.net> Sender: linux-net-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Thanks David. Would you mind giving me a bit of intuition why I can't have a 1:1 mapping of CPUs to NICs? I am a bit out of my depth here, but I'd like to learn. Best, Don David Miller wrote: > From: Don Porter > Date: Tue, 14 Oct 2008 14:05:34 -0500 > > >> It seems to me that with 4 independent NICs and plenty of CPUs to >> spare, I ought to be able to assign one softirq daemon to each NIC >> rather than funnelling all of the traffic through 1 or 2. >> > > Traffic doesn't get distributed unless the NIC has support > for RX flow seperation and PCI MSI-X interrupts. Your NICs > do not. > > So no matter how hard you try, each NIC is going to have it's > packets processed essentially on one cpu. >