From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tim Gardner Subject: Re: 2.6.35-rc2, CONFIG_RPS is filling the dmesg log Date: Wed, 09 Jun 2010 09:22:59 -0600 Message-ID: <4C0FB1D3.60901@canonical.com> References: <4C0EAE3E.4070708@canonical.com> <4C0F96B4.2000307@canonical.com> <1276090953.2442.140.camel@edumazet-laptop> Reply-To: tim.gardner@canonical.com Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------030206050901080004080903" Cc: netdev To: Eric Dumazet Return-path: Received: from mail.tpi.com ([70.99.223.143]:4469 "EHLO mail.tpi.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753790Ab0FIPXG (ORCPT ); Wed, 9 Jun 2010 11:23:06 -0400 In-Reply-To: <1276090953.2442.140.camel@edumazet-laptop> Sender: netdev-owner@vger.kernel.org List-ID: This is a multi-part message in MIME format. --------------030206050901080004080903 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 06/09/2010 07:42 AM, Eric Dumazet wrote: > Le mercredi 09 juin 2010 à 07:27 -0600, Tim Gardner a écrit : >> On 06/08/2010 02:55 PM, Tim Gardner wrote: >>> With 2.6.35-rc2 my dmesg log is being flooded with messages like this: >>> >>> br0 received packet on queue 4, but number of RX queues is 1 >>> >>> This machine is bridged for KVM and has 2 igb network adapters. >>> >>> The root cause appears to be CONFIG_RPS=y and the fact that none of the >>> drivers that call skb_record_rx_queue() perform their net device >>> allocation using alloc_netdev_mq(), thereby initializing num_rx_queues >>> to a maximum of 1. >>> >>> Given that this is early RPS days, is the warning in get_rps_cpu() >>> really necessary? It would appear that _all_ of the multi-receive queue >>> devices that call skb_record_rx_queue() will cause this log noise. >>> >>> By the way, how do you turn off CONFIG_RPS? The only way I could get it >>> disabled was to change the default in net/Kconfig to 'n'. >>> >>> rtg >> >> This is the route that I'm taking with Ubuntu in the short term. I'll >> have lots of server testers complaining pretty soon if I don't take care >> of this now. It does keep my server logs from filling. >> >> rtg >> > > Probably fine, but your commit message is not exact : > > So far no users of skb_record_rx_queue() use alloc_netdev_mq() for > network device initialization, so don't print a warning about num_rx_queues > imbalances in get_rps_cpu() unless they have actually been allocated. > > In fact, drivers that use skb_record_rx_queue() did use alloc_netdev_mq(). > > Problem is : packets going thru bridge/bonding that are not yet > multiqueue enabled. If R[PF]S enabled for these "virtual devices", > we trigger the get_rps_cpu() warning. > > Also, in a bonding setup, we still have a problem > because all tx packets will go thru tx queue 0 (dev_pick_tx() job) > > (That might be good to know that for Ubuntu server testers) > How about this? -- Tim Gardner tim.gardner@canonical.com --------------030206050901080004080903 Content-Type: text/x-patch; name="0001-UBUNTU-SAUCE-net-Print-num_rx_queues-imbalance-warni.patch" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename*0="0001-UBUNTU-SAUCE-net-Print-num_rx_queues-imbalance-warni.pa"; filename*1="tch" >>From ad76786a1a0c7b7b3c9bfeb4116fa0e2742f6328 Mon Sep 17 00:00:00 2001 From: Tim Gardner Date: Tue, 8 Jun 2010 17:51:27 -0600 Subject: [PATCH] net: Print num_rx_queues imbalance warning only when there are allocated queues BugLink: http://bugs.launchpad.net/bugs/591416 There are a number of network drivers (bridge, bonding, etc) that are not yet receive multi-queue enabled and use alloc_netdev(), so don't print a num_rx_queues imbalance warning in that case. Also, only print the warning once for those drivers that _are_ multi-queue enabled. Signed-off-by: Tim Gardner --- net/core/dev.c | 8 +++----- 1 files changed, 3 insertions(+), 5 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index d03470f..14a8568 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2253,11 +2253,9 @@ static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb, if (skb_rx_queue_recorded(skb)) { u16 index = skb_get_rx_queue(skb); if (unlikely(index >= dev->num_rx_queues)) { - if (net_ratelimit()) { - pr_warning("%s received packet on queue " - "%u, but number of RX queues is %u\n", - dev->name, index, dev->num_rx_queues); - } + WARN_ONCE(dev->num_rx_queues > 1, "%s received packet " + "on queue %u, but number of RX queues is %u\n", + dev->name, index, dev->num_rx_queues); goto done; } rxqueue = dev->_rx + index; -- 1.7.0.4 --------------030206050901080004080903--