diff mbox series

[v4,net-next,9/9] net: don't bother calling list RX functions on empty lists

Message ID 3c1622e7-8b8e-5dbe-47d9-a28ad14b2942@solarflare.com
State Accepted, archived
Delegated to: David Miller
Headers show
Series Handle multiple received packets at each stage | expand

Commit Message

Edward Cree July 2, 2018, 3:14 p.m. UTC 
Generally the check should be very cheap, as the sk_buff_head is in cache.

Signed-off-by: Edward Cree <ecree@solarflare.com>
---
 net/core/dev.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/net/core/dev.c b/net/core/dev.c
index 4c5ebfab9bc8..d6084b0cd9ce 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4773,7 +4773,8 @@  static void __netif_receive_skb_list(struct list_head *head)
 
 			/* Handle the previous sublist */
 			list_cut_before(&sublist, head, &skb->list);
-			__netif_receive_skb_list_core(&sublist, pfmemalloc);
+			if (!list_empty(&sublist))
+				__netif_receive_skb_list_core(&sublist, pfmemalloc);
 			pfmemalloc = !pfmemalloc;
 			/* See comments in __netif_receive_skb */
 			if (pfmemalloc)
@@ -4783,7 +4784,8 @@  static void __netif_receive_skb_list(struct list_head *head)
 		}
 	}
 	/* Handle the remaining sublist */
-	__netif_receive_skb_list_core(head, pfmemalloc);
+	if (!list_empty(head))
+		__netif_receive_skb_list_core(head, pfmemalloc);
 	/* Restore pflags */
 	if (pfmemalloc)
 		memalloc_noreclaim_restore(noreclaim_flag);
@@ -4944,6 +4946,8 @@  void netif_receive_skb_list(struct list_head *head)
 {
 	struct sk_buff *skb;
 
+	if (list_empty(head))
+		return;
 	list_for_each_entry(skb, head, list)
 		trace_netif_receive_skb_list_entry(skb);
 	netif_receive_skb_list_internal(head);