[NET]: Can use __get_cpu_var() instead of per_cpu() in loopback driver.

As BHs are off in loopback_xmit(), preemption cannot occurs, so we can
use __get_cpu_var() instead of per_cpu() (and avoid a
preempt_enable()/preempt_disable() pair)

Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
index 93fbea1c9271..82c10dec1b5a 100644
--- a/drivers/net/loopback.c
+++ b/drivers/net/loopback.c
@@ -153,14 +153,14 @@ static int loopback_xmit(struct sk_buff *skb, struct net_device *dev)
 #endif
         dev->last_rx = jiffies;
 
-        lb_stats = &per_cpu(pcpu_lstats, get_cpu());
+        /* it's OK to use __get_cpu_var() because BHs are off */
+        lb_stats = &__get_cpu_var(pcpu_lstats);
         lb_stats->bytes += skb->len;
         lb_stats->packets++;
-        put_cpu();
 
         netif_rx(skb);
 
-        return(0);
+        return 0;
 }
 
 static struct net_device_stats loopback_stats;