From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761320AbZCRWAU (ORCPT ); Wed, 18 Mar 2009 18:00:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761214AbZCRV6g (ORCPT ); Wed, 18 Mar 2009 17:58:36 -0400 Received: from one.firstfloor.org ([213.235.205.2]:54732 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761188AbZCRV6e (ORCPT ); Wed, 18 Mar 2009 17:58:34 -0400 Date: Wed, 18 Mar 2009 22:59:01 +0100 From: Andi Kleen To: Vernon Mauery Cc: Eilon Greenstein , Andi Kleen , netdev , LKML , rt-users Subject: Re: High contention on the sk_buff_head.lock Message-ID: <20090318215901.GV11935@one.firstfloor.org> References: <49C12E64.1000301@us.ibm.com> <87prge1rhu.fsf@basil.nowhere.org> <49C16294.8050101@us.ibm.com> <1237412732.29116.2.camel@lb-tlvb-eliezer> <49C16CD4.3010708@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49C16CD4.3010708@us.ibm.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > Thanks. I will test to see how this affects this lock contention the > next time the broadcom hardware is available. The other strategy to reduce lock contention here is to use TSO/GSO/USO. With that the lock has to be taken less often because there are less packets travelling down the stack. I'm not sure how well that works with netperf style workloads though. Using multiple TX queues is probably better though if you have capable hardware. Or ideally both. -Andi -- ak@linux.intel.com -- Speaking for myself only.