warn: Turn the netdev timeout WARN_ON() into a WARN()

this patch turns the netdev timeout WARN_ON_ONCE() into a WARN_ONCE(),
so that the device and driver names are inside the warning message.
This helps automated tools like kerneloops.org to collect the data
and do statistics, as well as making it more likely that humans
cut-n-paste the important message as part of a bugreport.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/asm-generic/bug.h

@@ -97,6 +97,16 @@ extern void warn_slowpath(const char *file, const int line,
 	unlikely(__ret_warn_once);				\
 })
 
+#define WARN_ONCE(condition, format...)	({			\
+	static int __warned;					\
+	int __ret_warn_once = !!(condition);			\
+								\
+	if (unlikely(__ret_warn_once))				\
+		if (WARN(!__warned, format)) 			\
+			__warned = 1;				\
+	unlikely(__ret_warn_once);				\
+})
+
 #define WARN_ON_RATELIMIT(condition, state)			\
 		WARN_ON((condition) && __ratelimit(state))
 

net/sched/sch_generic.c

@@ -215,10 +215,9 @@ static void dev_watchdog(unsigned long arg)
 			    time_after(jiffies, (dev->trans_start +
 						 dev->watchdog_timeo))) {
 				char drivername[64];
-				printk(KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit timed out\n",
+				WARN_ONCE(1, KERN_INFO "NETDEV WATCHDOG: %s (%s): transmit timed out\n",
 				       dev->name, netdev_drivername(dev, drivername, 64));
 				dev->tx_timeout(dev);
-				WARN_ON_ONCE(1);
 			}
 			if (!mod_timer(&dev->watchdog_timer,
 				       round_jiffies(jiffies +