[NET]: Separate two usages of netdev_max_backlog.

Separate out the two uses of netdev_max_backlog. One controls the
upper bound on packets processed per softirq, the new name for this is
netdev_budget; the other controls the limit on packets queued via
netif_rx.

Increase the max_backlog default to account for faster processors.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/sysctl.h

@@ -243,6 +243,7 @@ enum
 	NET_CORE_MOD_CONG=16,
 	NET_CORE_DEV_WEIGHT=17,
 	NET_CORE_SOMAXCONN=18,
+	NET_CORE_BUDGET=19,
 };
 
 /* /proc/sys/net/ethernet */

net/core/dev.c

@@ -1346,7 +1346,8 @@ int dev_queue_xmit(struct sk_buff *skb)
 			Receiver routines
   =======================================================================*/
 
-int netdev_max_backlog = 300;
+int netdev_max_backlog = 1000;
+int netdev_budget = 300;
 int weight_p = 64;            /* old backlog weight */
 
 DEFINE_PER_CPU(struct netif_rx_stats, netdev_rx_stat) = { 0, };
@@ -1695,8 +1696,7 @@ static void net_rx_action(struct softirq_action *h)
 {
 	struct softnet_data *queue = &__get_cpu_var(softnet_data);
 	unsigned long start_time = jiffies;
-	int budget = netdev_max_backlog;
-
+	int budget = netdev_budget;
 
 	local_irq_disable();
 

net/core/sysctl_net_core.c

@@ -13,6 +13,7 @@
 #ifdef CONFIG_SYSCTL
 
 extern int netdev_max_backlog;
+extern int netdev_budget;
 extern int weight_p;
 extern int net_msg_cost;
 extern int net_msg_burst;
@@ -124,6 +125,14 @@ ctl_table core_table[] = {
 		.mode		= 0644,
 		.proc_handler	= &proc_dointvec
 	},
+	{
+		.ctl_name	= NET_CORE_BUDGET,
+		.procname	= "netdev_budget",
+		.data		= &netdev_budget,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec
+	},
 	{ .ctl_name = 0 }
 };