* 2.6.35-rc2, CONFIG_RPS is filling the dmesg log @ 2010-06-08 20:55 Tim Gardner 2010-06-09 13:27 ` Tim Gardner 0 siblings, 1 reply; 5+ messages in thread From: Tim Gardner @ 2010-06-08 20:55 UTC (permalink / raw) To: netdev 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 -- Tim Gardner tim.gardner@canonical.com ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: 2.6.35-rc2, CONFIG_RPS is filling the dmesg log 2010-06-08 20:55 2.6.35-rc2, CONFIG_RPS is filling the dmesg log Tim Gardner @ 2010-06-09 13:27 ` Tim Gardner 2010-06-09 13:42 ` Eric Dumazet 0 siblings, 1 reply; 5+ messages in thread From: Tim Gardner @ 2010-06-09 13:27 UTC (permalink / raw) To: netdev [-- Attachment #1: Type: text/plain, Size: 1093 bytes --] 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 -- Tim Gardner tim.gardner@canonical.com [-- Attachment #2: 0001-net-Print-num_rx_queues-imbalance-warning-only-when-.patch --] [-- Type: text/x-patch, Size: 1210 bytes --] >From 02598ea1409568654a554fae3ac2c22ecc2474d0 Mon Sep 17 00:00:00 2001 From: Tim Gardner <tim.gardner@canonical.com> 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 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. Signed-off-by: Tim Gardner <tim.gardner@canonical.com> --- net/core/dev.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index d03470f..0852608 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -2253,7 +2253,7 @@ 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()) { + if (dev->num_rx_queues > 1 && 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); -- 1.7.0.4 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: 2.6.35-rc2, CONFIG_RPS is filling the dmesg log 2010-06-09 13:27 ` Tim Gardner @ 2010-06-09 13:42 ` Eric Dumazet 2010-06-09 15:22 ` Tim Gardner 0 siblings, 1 reply; 5+ messages in thread From: Eric Dumazet @ 2010-06-09 13:42 UTC (permalink / raw) To: tim.gardner; +Cc: netdev 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) ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: 2.6.35-rc2, CONFIG_RPS is filling the dmesg log 2010-06-09 13:42 ` Eric Dumazet @ 2010-06-09 15:22 ` Tim Gardner 2010-06-09 15:27 ` Eric Dumazet 0 siblings, 1 reply; 5+ messages in thread From: Tim Gardner @ 2010-06-09 15:22 UTC (permalink / raw) To: Eric Dumazet; +Cc: netdev [-- Attachment #1: Type: text/plain, Size: 2011 bytes --] 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 [-- Attachment #2: 0001-UBUNTU-SAUCE-net-Print-num_rx_queues-imbalance-warni.patch --] [-- Type: text/x-patch, Size: 1443 bytes --] >From ad76786a1a0c7b7b3c9bfeb4116fa0e2742f6328 Mon Sep 17 00:00:00 2001 From: Tim Gardner <tim.gardner@canonical.com> 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 <tim.gardner@canonical.com> --- 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 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: 2.6.35-rc2, CONFIG_RPS is filling the dmesg log 2010-06-09 15:22 ` Tim Gardner @ 2010-06-09 15:27 ` Eric Dumazet 0 siblings, 0 replies; 5+ messages in thread From: Eric Dumazet @ 2010-06-09 15:27 UTC (permalink / raw) To: tim.gardner; +Cc: netdev Le mercredi 09 juin 2010 à 09:22 -0600, Tim Gardner a écrit : > 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? > Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Thanks ! ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2010-06-09 15:27 UTC | newest] Thread overview: 5+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2010-06-08 20:55 2.6.35-rc2, CONFIG_RPS is filling the dmesg log Tim Gardner 2010-06-09 13:27 ` Tim Gardner 2010-06-09 13:42 ` Eric Dumazet 2010-06-09 15:22 ` Tim Gardner 2010-06-09 15:27 ` Eric Dumazet
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