e1000: implement more efficient tx queue locking
Implement more efficient locking (avoid the lock) when checking for
a stopped queue. Also don't wake the queue unless the threshold is
reached to avoid queue on/off thrash.
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: John Ronciak <john.ronciak@intel.com>
diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index f604a1d..3c37c40 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -3400,13 +3400,15 @@
tx_ring->next_to_clean = i;
- spin_lock(&tx_ring->tx_lock);
-
+#define TX_WAKE_THRESHOLD 32
if (unlikely(cleaned && netif_queue_stopped(netdev) &&
- netif_carrier_ok(netdev)))
- netif_wake_queue(netdev);
-
- spin_unlock(&tx_ring->tx_lock);
+ netif_carrier_ok(netdev))) {
+ spin_lock(&tx_ring->tx_lock);
+ if (netif_queue_stopped(netdev) &&
+ (E1000_DESC_UNUSED(tx_ring) >= TX_WAKE_THRESHOLD))
+ netif_wake_queue(netdev);
+ spin_unlock(&tx_ring->tx_lock);
+ }
if (adapter->detect_tx_hung) {
/* Detect a transmit hang in hardware, this serializes the