From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vernon Mauery Subject: Re: High contention on the sk_buff_head.lock Date: Wed, 18 Mar 2009 14:51:16 -0700 Message-ID: <49C16CD4.3010708@us.ibm.com> References: <49C12E64.1000301@us.ibm.com> <87prge1rhu.fsf@basil.nowhere.org> <49C16294.8050101@us.ibm.com> <1237412732.29116.2.camel@lb-tlvb-eliezer> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Andi Kleen , netdev , LKML , rt-users To: Eilon Greenstein Return-path: In-Reply-To: <1237412732.29116.2.camel@lb-tlvb-eliezer> Sender: linux-rt-users-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Eilon Greenstein wrote: > On Wed, 2009-03-18 at 14:07 -0700, Vernon Mauery wrote: >>> The real "fix" would be probably to use a multi queue capable NIC >>> and a NIC driver that sets up multiple queues for TX (normally they >>> only do for RX). Then cores or a set of cores (often the number >>> of cores is larger than the number of NIC queues) could avoid this >>> problem. Disadvantage: more memory use. >> Hmmm. So do either the netxen_nic or bnx2x drivers support multiple >> queues? (that is the HW that I have access to right now). And do I >> need to do anything to set them up? >> > The version of bnx2x in net-next support multi Tx queues (and Rx). It > will open an equal number of Tx and Rx queues up to 16 or the number of > cores in the system. You can validate that all queues are transmitting > with "ethtool -S" which has per queue statistics in that version. Thanks. I will test to see how this affects this lock contention the next time the broadcom hardware is available. --Vernon