From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Re: pktgen and spin_lock_bh in xmit path Date: Tue, 20 Oct 2009 14:30:40 -0700 Message-ID: <4ADE2C00.8030900@candelatech.com> References: <4ADD309B.1040505@candelatech.com> <4ADD32FA.6030409@gmail.com> <4ADD41F5.5080707@candelatech.com> <4ADDF560.1020509@candelatech.com> <4ADDF6E5.4070509@gmail.com> <4ADDF948.1050208@candelatech.com> <4ADE0306.6060101@gmail.com> <4ADE0770.8060708@gmail.com> <4ADE2735.9000807@candelatech.com> <4ADE2A24.6080300@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: NetDev , robert@herjulf.net, "David S. Miller" To: Eric Dumazet Return-path: Received: from mail.candelatech.com ([208.74.158.172]:39108 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750909AbZJTVak (ORCPT ); Tue, 20 Oct 2009 17:30:40 -0400 In-Reply-To: <4ADE2A24.6080300@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On 10/20/2009 02:22 PM, Eric Dumazet wrote: > Problem is skb->queue_mapping has different meaning if skb is directly given to a real device -> start_xmit() > > ( In this case skb->queue_mapping should be between [O ... real_num_tx_queues-1]) > > But if it goes through dev_queue_xmit(), it should be set between [1 .. real_num_tx_queues], because > dev_pick_tx() will decrement skb->queue_mapping > > In fact skb->queue_mapping only works for forwarded packets, not locally generated ones. > > I am too tired to cook a fix at this moment, sorry :( That's definitely a nasty little issue. Using skb_set_queue_mapping in pktgen makes it run for me, but may just be getting lucky with the mac-vlan interfaces which will do the dev_queue_xmit (but, I don't so much care exactly what queue is used as long as things don't crash and the link doesn't reset). Don't worry about a quick patch on my account. I seem to have it working to at least some degree (no funny crashes, no link watchdog timeouts). Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com