From b9f463d6c9849230043123a6335d59ac7fea4d5a Mon Sep 17 00:00:00 2001 From: Edward Cree Date: Mon, 2 Jul 2018 16:14:44 +0100 Subject: net: don't bother calling list RX functions on empty lists Generally the check should be very cheap, as the sk_buff_head is in cache. Signed-off-by: Edward Cree Signed-off-by: David S. Miller --- net/core/dev.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'net/core') diff --git a/net/core/dev.c b/net/core/dev.c index 5e22719ce71d..7e6a2f66db5c 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4887,7 +4887,8 @@ 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) @@ -4897,7 +4898,8 @@ 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); @@ -5058,6 +5060,8 @@ 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); -- cgit v1.2.3