diff mbox

mac80211: NOHZ: local_softirq_pending 08

Message ID 200909111707.23971.mb@bu3sch.de (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Michael Buesch Sept. 11, 2009, 3:07 p.m. UTC
On Friday 11 September 2009 16:57:54 Kalle Valo wrote:
> Michael Buesch <mb@bu3sch.de> writes:
> 
> > Hi,
> 
> Hallo,
> 
> > mac80211 (or some other part of the networking stack) triggers this
> > warning in the NOHZ code: NOHZ: local_softirq_pending 08
> >
> > 08 seems to be NET_RX_SOFTIRQ.
> >
> > It happens, because my test driver b43 handles all RX and TX-status
> > callbacks in process context. I guess some part of the networking
> > stack expects RX to be in tasklet and/or softirq context.
> >
> > We also have a report of this warning in wl1251, so it's probably not
> > a b43 problem.
> 
> Yes, I see this with wl1251. It uses workqueues everywhere.
> 

This patch seems to fix it.

Signed-off-by: Michael Buesch <mb@bu3sch.de>

Comments

Kalle Valo Sept. 11, 2009, 4:07 p.m. UTC | #1
Michael Buesch <mb@bu3sch.de> writes:

>> > mac80211 (or some other part of the networking stack) triggers this
>> > warning in the NOHZ code: NOHZ: local_softirq_pending 08
>> >
>> > 08 seems to be NET_RX_SOFTIRQ.
>> >
>> > It happens, because my test driver b43 handles all RX and TX-status
>> > callbacks in process context. I guess some part of the networking
>> > stack expects RX to be in tasklet and/or softirq context.
>> >
>> > We also have a report of this warning in wl1251, so it's probably not
>> > a b43 problem.
>> 
>> Yes, I see this with wl1251. It uses workqueues everywhere.
>> 
>
> This patch seems to fix it.

Yes, it does. Thanks.

> Signed-off-by: Michael Buesch <mb@bu3sch.de>

Tested-by: Kalle Valo <kalle.valo@nokia.com>
Oliver Hartkopp Sept. 11, 2009, 4:07 p.m. UTC | #2
Michael Buesch wrote:
> On Friday 11 September 2009 16:57:54 Kalle Valo wrote:
>> Michael Buesch <mb@bu3sch.de> writes:
>>
>>> Hi,
>> Hallo,
>>
>>> mac80211 (or some other part of the networking stack) triggers this
>>> warning in the NOHZ code: NOHZ: local_softirq_pending 08
>>>
>>> 08 seems to be NET_RX_SOFTIRQ.
>>>
>>> It happens, because my test driver b43 handles all RX and TX-status
>>> callbacks in process context. I guess some part of the networking
>>> stack expects RX to be in tasklet and/or softirq context.
>>>
>>> We also have a report of this warning in wl1251, so it's probably not
>>> a b43 problem.
>> Yes, I see this with wl1251. It uses workqueues everywhere.
>>
> 
> This patch seems to fix it.
> 
> Signed-off-by: Michael Buesch <mb@bu3sch.de>
> 
> Index: wireless-testing/net/mac80211/cfg.c
> ===================================================================
> --- wireless-testing.orig/net/mac80211/cfg.c	2009-08-09 18:47:11.000000000 +0200
> +++ wireless-testing/net/mac80211/cfg.c	2009-09-11 16:59:12.000000000 +0200
> @@ -606,7 +606,7 @@ static void ieee80211_send_layer2_update
>  	skb->dev = sta->sdata->dev;
>  	skb->protocol = eth_type_trans(skb, sta->sdata->dev);
>  	memset(skb->cb, 0, sizeof(skb->cb));
> -	netif_rx(skb);
> +	ieee80211_netif_rx(skb);
>  }
>  
>  static void sta_apply_parameters(struct ieee80211_local *local,
> Index: wireless-testing/net/mac80211/ieee80211_i.h
> ===================================================================
> --- wireless-testing.orig/net/mac80211/ieee80211_i.h	2009-08-23 00:06:41.000000000 +0200
> +++ wireless-testing/net/mac80211/ieee80211_i.h	2009-09-11 17:02:05.000000000 +0200
> @@ -1053,6 +1053,14 @@ void ieee80211_tx_pending(unsigned long 
>  int ieee80211_monitor_start_xmit(struct sk_buff *skb, struct net_device *dev);
>  int ieee80211_subif_start_xmit(struct sk_buff *skb, struct net_device *dev);
>  
> +/* rx handling */
> +static inline int ieee80211_netif_rx(struct sk_buff *skb)
> +{
> +	if (in_interrupt())
> +		return netif_rx(skb);
> +	return netif_rx_ni(skb);
> +}
> +

Hello Michael,

i know this NOHZ warning from the CAN stack also - but now, i know what caused
this warning. I fixed it in my local tree and it works. Thanks!

As there are several users in the kernel do exact this test and call the
appropriate netif_rx() function, i would suggest to create a static inline
function:

static inline int netif_rx_ti(struct sk_buff *skb)
{
	if (in_interrupt())
		return netif_rx(skb);
	return netif_rx_ni(skb);
}

('ti' for test in_interrupt())

in include/linux/netdevice.h

What do you think about that?

Regards,
Oliver
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Michael Buesch Sept. 11, 2009, 4:13 p.m. UTC | #3
On Friday 11 September 2009 18:07:39 Oliver Hartkopp wrote:
> Michael Buesch wrote:
> > On Friday 11 September 2009 16:57:54 Kalle Valo wrote:
> >> Michael Buesch <mb@bu3sch.de> writes:
> >>
> >>> Hi,
> >> Hallo,
> >>
> >>> mac80211 (or some other part of the networking stack) triggers this
> >>> warning in the NOHZ code: NOHZ: local_softirq_pending 08
> >>>
> >>> 08 seems to be NET_RX_SOFTIRQ.
> >>>
> >>> It happens, because my test driver b43 handles all RX and TX-status
> >>> callbacks in process context. I guess some part of the networking
> >>> stack expects RX to be in tasklet and/or softirq context.
> >>>
> >>> We also have a report of this warning in wl1251, so it's probably not
> >>> a b43 problem.
> >> Yes, I see this with wl1251. It uses workqueues everywhere.
> >>
> > 
> > This patch seems to fix it.
> > 
> > Signed-off-by: Michael Buesch <mb@bu3sch.de>
> > 
> > Index: wireless-testing/net/mac80211/cfg.c
> > ===================================================================
> > --- wireless-testing.orig/net/mac80211/cfg.c	2009-08-09 18:47:11.000000000 +0200
> > +++ wireless-testing/net/mac80211/cfg.c	2009-09-11 16:59:12.000000000 +0200
> > @@ -606,7 +606,7 @@ static void ieee80211_send_layer2_update
> >  	skb->dev = sta->sdata->dev;
> >  	skb->protocol = eth_type_trans(skb, sta->sdata->dev);
> >  	memset(skb->cb, 0, sizeof(skb->cb));
> > -	netif_rx(skb);
> > +	ieee80211_netif_rx(skb);
> >  }
> >  
> >  static void sta_apply_parameters(struct ieee80211_local *local,
> > Index: wireless-testing/net/mac80211/ieee80211_i.h
> > ===================================================================
> > --- wireless-testing.orig/net/mac80211/ieee80211_i.h	2009-08-23 00:06:41.000000000 +0200
> > +++ wireless-testing/net/mac80211/ieee80211_i.h	2009-09-11 17:02:05.000000000 +0200
> > @@ -1053,6 +1053,14 @@ void ieee80211_tx_pending(unsigned long 
> >  int ieee80211_monitor_start_xmit(struct sk_buff *skb, struct net_device *dev);
> >  int ieee80211_subif_start_xmit(struct sk_buff *skb, struct net_device *dev);
> >  
> > +/* rx handling */
> > +static inline int ieee80211_netif_rx(struct sk_buff *skb)
> > +{
> > +	if (in_interrupt())
> > +		return netif_rx(skb);
> > +	return netif_rx_ni(skb);
> > +}
> > +
> 
> Hello Michael,
> 
> i know this NOHZ warning from the CAN stack also - but now, i know what caused
> this warning. I fixed it in my local tree and it works. Thanks!
> 
> As there are several users in the kernel do exact this test and call the
> appropriate netif_rx() function, i would suggest to create a static inline
> function:
> 
> static inline int netif_rx_ti(struct sk_buff *skb)
> {
> 	if (in_interrupt())
> 		return netif_rx(skb);
> 	return netif_rx_ni(skb);
> }
> 
> ('ti' for test in_interrupt())
> 
> in include/linux/netdevice.h
> 
> What do you think about that?

Yeah, I'm fine with that.
diff mbox

Patch

Index: wireless-testing/net/mac80211/cfg.c
===================================================================
--- wireless-testing.orig/net/mac80211/cfg.c	2009-08-09 18:47:11.000000000 +0200
+++ wireless-testing/net/mac80211/cfg.c	2009-09-11 16:59:12.000000000 +0200
@@ -606,7 +606,7 @@  static void ieee80211_send_layer2_update
 	skb->dev = sta->sdata->dev;
 	skb->protocol = eth_type_trans(skb, sta->sdata->dev);
 	memset(skb->cb, 0, sizeof(skb->cb));
-	netif_rx(skb);
+	ieee80211_netif_rx(skb);
 }
 
 static void sta_apply_parameters(struct ieee80211_local *local,
Index: wireless-testing/net/mac80211/ieee80211_i.h
===================================================================
--- wireless-testing.orig/net/mac80211/ieee80211_i.h	2009-08-23 00:06:41.000000000 +0200
+++ wireless-testing/net/mac80211/ieee80211_i.h	2009-09-11 17:02:05.000000000 +0200
@@ -1053,6 +1053,14 @@  void ieee80211_tx_pending(unsigned long 
 int ieee80211_monitor_start_xmit(struct sk_buff *skb, struct net_device *dev);
 int ieee80211_subif_start_xmit(struct sk_buff *skb, struct net_device *dev);
 
+/* rx handling */
+static inline int ieee80211_netif_rx(struct sk_buff *skb)
+{
+	if (in_interrupt())
+		return netif_rx(skb);
+	return netif_rx_ni(skb);
+}
+
 /* HT */
 void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_supported_band *sband,
 				       struct ieee80211_ht_cap *ht_cap_ie,
Index: wireless-testing/net/mac80211/main.c
===================================================================
--- wireless-testing.orig/net/mac80211/main.c	2009-08-23 00:06:41.000000000 +0200
+++ wireless-testing/net/mac80211/main.c	2009-09-11 16:59:35.000000000 +0200
@@ -591,7 +591,7 @@  void ieee80211_tx_status(struct ieee8021
 				skb2 = skb_clone(skb, GFP_ATOMIC);
 				if (skb2) {
 					skb2->dev = prev_dev;
-					netif_rx(skb2);
+					ieee80211_netif_rx(skb2);
 				}
 			}
 
@@ -600,7 +600,7 @@  void ieee80211_tx_status(struct ieee8021
 	}
 	if (prev_dev) {
 		skb->dev = prev_dev;
-		netif_rx(skb);
+		ieee80211_netif_rx(skb);
 		skb = NULL;
 	}
 	rcu_read_unlock();
Index: wireless-testing/net/mac80211/rx.c
===================================================================
--- wireless-testing.orig/net/mac80211/rx.c	2009-09-04 19:08:05.000000000 +0200
+++ wireless-testing/net/mac80211/rx.c	2009-09-11 17:00:08.000000000 +0200
@@ -309,7 +309,7 @@  ieee80211_rx_monitor(struct ieee80211_lo
 			skb2 = skb_clone(skb, GFP_ATOMIC);
 			if (skb2) {
 				skb2->dev = prev_dev;
-				netif_rx(skb2);
+				ieee80211_netif_rx(skb2);
 			}
 		}
 
@@ -320,7 +320,7 @@  ieee80211_rx_monitor(struct ieee80211_lo
 
 	if (prev_dev) {
 		skb->dev = prev_dev;
-		netif_rx(skb);
+		ieee80211_netif_rx(skb);
 	} else
 		dev_kfree_skb(skb);
 
@@ -1349,7 +1349,7 @@  ieee80211_deliver_skb(struct ieee80211_r
 			/* deliver to local stack */
 			skb->protocol = eth_type_trans(skb, dev);
 			memset(skb->cb, 0, sizeof(skb->cb));
-			netif_rx(skb);
+			ieee80211_netif_rx(skb);
 		}
 	}
 
@@ -1943,7 +1943,7 @@  static void ieee80211_rx_cooked_monitor(
 			skb2 = skb_clone(skb, GFP_ATOMIC);
 			if (skb2) {
 				skb2->dev = prev_dev;
-				netif_rx(skb2);
+				ieee80211_netif_rx(skb2);
 			}
 		}
 
@@ -1954,7 +1954,7 @@  static void ieee80211_rx_cooked_monitor(
 
 	if (prev_dev) {
 		skb->dev = prev_dev;
-		netif_rx(skb);
+		ieee80211_netif_rx(skb);
 		skb = NULL;
 	} else
 		goto out_free_skb;