1 files changed, 43 insertions, 25 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
index ebf778df58cd..40be481268de 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4316,20 +4316,28 @@ static void net_rps_action_and_irq_enable(struct softnet_data *sd)
 		local_irq_enable();
 }
 
+static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
+{
+#ifdef CONFIG_RPS
+	return sd->rps_ipi_list != NULL;
+#else
+	return false;
+#endif
+}
+
 static int process_backlog(struct napi_struct *napi, int quota)
 {
 	int work = 0;
 	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
 
-#ifdef CONFIG_RPS
 	/* Check if we have pending ipi, its better to send them now,
 	 * not waiting net_rx_action() end.
 	 */
-	if (sd->rps_ipi_list) {
+	if (sd_has_rps_ipi_waiting(sd)) {
 		local_irq_disable();
 		net_rps_action_and_irq_enable(sd);
 	}
-#endif
+
 	napi->weight = weight_p;
 	local_irq_disable();
 	while (1) {
@@ -4356,7 +4364,6 @@ static int process_backlog(struct napi_struct *napi, int quota)
 			 * We can use a plain write instead of clear_bit(),
 			 * and we dont need an smp_mb() memory barrier.
 			 */
-			list_del(&napi->poll_list);
 			napi->state = 0;
 			rps_unlock(sd);
 
@@ -4406,7 +4413,7 @@ void __napi_complete(struct napi_struct *n)
 	BUG_ON(!test_bit(NAPI_STATE_SCHED, &n->state));
 	BUG_ON(n->gro_list);
 
-	list_del(&n->poll_list);
+	list_del_init(&n->poll_list);
 	smp_mb__before_atomic();
 	clear_bit(NAPI_STATE_SCHED, &n->state);
 }
@@ -4424,9 +4431,15 @@ void napi_complete(struct napi_struct *n)
 		return;
 
 	napi_gro_flush(n, false);
-	local_irq_save(flags);
-	__napi_complete(n);
-	local_irq_restore(flags);
+
+	if (likely(list_empty(&n->poll_list))) {
+		WARN_ON_ONCE(!test_and_clear_bit(NAPI_STATE_SCHED, &n->state));
+	} else {
+		/* If n->poll_list is not empty, we need to mask irqs */
+		local_irq_save(flags);
+		__napi_complete(n);
+		local_irq_restore(flags);
+	}
 }
 EXPORT_SYMBOL(napi_complete);
 
@@ -4520,29 +4533,28 @@ static void net_rx_action(struct softirq_action *h)
 	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
 	unsigned long time_limit = jiffies + 2;
 	int budget = netdev_budget;
+	LIST_HEAD(list);
+	LIST_HEAD(repoll);
 	void *have;
 
 	local_irq_disable();
+	list_splice_init(&sd->poll_list, &list);
+	local_irq_enable();
 
-	while (!list_empty(&sd->poll_list)) {
+	while (!list_empty(&list)) {
 		struct napi_struct *n;
 		int work, weight;
 
-		/* If softirq window is exhuasted then punt.
+		/* If softirq window is exhausted then punt.
 		 * Allow this to run for 2 jiffies since which will allow
 		 * an average latency of 1.5/HZ.
 		 */
 		if (unlikely(budget <= 0 || time_after_eq(jiffies, time_limit)))
 			goto softnet_break;
 
-		local_irq_enable();
 
-		/* Even though interrupts have been re-enabled, this
-		 * access is safe because interrupts can only add new
-		 * entries to the tail of this list, and only ->poll()
-		 * calls can remove this head entry from the list.
-		 */
-		n = list_first_entry(&sd->poll_list, struct napi_struct, poll_list);
+		n = list_first_entry(&list, struct napi_struct, poll_list);
+		list_del_init(&n->poll_list);
 
 		have = netpoll_poll_lock(n);
 
@@ -4564,8 +4576,6 @@ static void net_rx_action(struct softirq_action *h)
 
 		budget -= work;
 
-		local_irq_disable();
-
 		/* Drivers must not modify the NAPI state if they
 		 * consume the entire weight.  In such cases this code
 		 * still "owns" the NAPI instance and therefore can
@@ -4573,32 +4583,40 @@ static void net_rx_action(struct softirq_action *h)
 		 */
 		if (unlikely(work == weight)) {
 			if (unlikely(napi_disable_pending(n))) {
-				local_irq_enable();
 				napi_complete(n);
-				local_irq_disable();
 			} else {
 				if (n->gro_list) {
 					/* flush too old packets
 					 * If HZ < 1000, flush all packets.
 					 */
-					local_irq_enable();
 					napi_gro_flush(n, HZ >= 1000);
-					local_irq_disable();
 				}
-				list_move_tail(&n->poll_list, &sd->poll_list);
+				list_add_tail(&n->poll_list, &repoll);
 			}
 		}
 
 		netpoll_poll_unlock(have);
 	}
+
+	if (!sd_has_rps_ipi_waiting(sd) &&
+	    list_empty(&list) &&
+	    list_empty(&repoll))
+		return;
 out:
+	local_irq_disable();
+
+	list_splice_tail_init(&sd->poll_list, &list);
+	list_splice_tail(&repoll, &list);
+	list_splice(&list, &sd->poll_list);
+	if (!list_empty(&sd->poll_list))
+		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
+
 	net_rps_action_and_irq_enable(sd);
 
 	return;
 
 softnet_break:
 	sd->time_squeeze++;
-	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
 	goto out;
 }