virtio-net: split out clean affinity function

Split out the clean affinity function to virtnet_clean_affinity().

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Eric Dumazet <erdnetdev@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: virtualization@lists.linux-foundation.org
Cc: netdev@vger.kernel.org
Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/virtio_net.c

@@ -1016,29 +1016,46 @@ static int virtnet_vlan_rx_kill_vid(struct net_device *dev, u16 vid)
 	return 0;
 }
 
-static void virtnet_set_affinity(struct virtnet_info *vi, bool set)
+static void virtnet_clean_affinity(struct virtnet_info *vi, long hcpu)
 {
 	int i;
 	int cpu;
 
-	/* In multiqueue mode, when the number of cpu is equal to the number of
-	 * queue pairs, we let the queue pairs to be private to one cpu by
-	 * setting the affinity hint to eliminate the contention.
-	 */
-	if ((vi->curr_queue_pairs == 1 ||
-	     vi->max_queue_pairs != num_online_cpus()) && set) {
 	if (vi->affinity_hint_set) {
-			set = false;
-		} else {
+		for (i = 0; i < vi->max_queue_pairs; i++) {
+			virtqueue_set_affinity(vi->rq[i].vq, -1);
+			virtqueue_set_affinity(vi->sq[i].vq, -1);
+		}
+
+		vi->affinity_hint_set = false;
+	}
+
 	i = 0;
-			for_each_online_cpu(cpu)
+	for_each_online_cpu(cpu) {
+		if (cpu == hcpu) {
+			*per_cpu_ptr(vi->vq_index, cpu) = -1;
+		} else {
 			*per_cpu_ptr(vi->vq_index, cpu) =
 				++i % vi->curr_queue_pairs;
-			return;
 		}
 	}
+}
+
+static void virtnet_set_affinity(struct virtnet_info *vi)
+{
+	int i;
+	int cpu;
+
+	/* In multiqueue mode, when the number of cpu is equal to the number of
+	 * queue pairs, we let the queue pairs to be private to one cpu by
+	 * setting the affinity hint to eliminate the contention.
+	 */
+	if (vi->curr_queue_pairs == 1 ||
+	    vi->max_queue_pairs != num_online_cpus()) {
+		virtnet_clean_affinity(vi, -1);
+		return;
+	}
 
-	if (set) {
 	i = 0;
 	for_each_online_cpu(cpu) {
 		virtqueue_set_affinity(vi->rq[i].vq, cpu);
@@ -1048,19 +1065,6 @@ static void virtnet_set_affinity(struct virtnet_info *vi, bool set)
 	}
 
 	vi->affinity_hint_set = true;
-	} else {
-		for(i = 0; i < vi->max_queue_pairs; i++) {
-			virtqueue_set_affinity(vi->rq[i].vq, -1);
-			virtqueue_set_affinity(vi->sq[i].vq, -1);
-		}
-
-		i = 0;
-		for_each_online_cpu(cpu)
-			*per_cpu_ptr(vi->vq_index, cpu) =
-				++i % vi->curr_queue_pairs;
-
-		vi->affinity_hint_set = false;
-	}
 }
 
 static void virtnet_get_ringparam(struct net_device *dev,
@@ -1110,7 +1114,7 @@ static int virtnet_set_channels(struct net_device *dev,
 		netif_set_real_num_tx_queues(dev, queue_pairs);
 		netif_set_real_num_rx_queues(dev, queue_pairs);
 
-		virtnet_set_affinity(vi, true);
+		virtnet_set_affinity(vi);
 	}
 	put_online_cpus();
 
@@ -1279,7 +1283,7 @@ static void virtnet_del_vqs(struct virtnet_info *vi)
 {
 	struct virtio_device *vdev = vi->vdev;
 
-	virtnet_set_affinity(vi, false);
+	virtnet_clean_affinity(vi, -1);
 
 	vdev->config->del_vqs(vdev);
 
@@ -1403,7 +1407,7 @@ static int init_vqs(struct virtnet_info *vi)
 		goto err_free;
 
 	get_online_cpus();
-	virtnet_set_affinity(vi, true);
+	virtnet_set_affinity(vi);
 	put_online_cpus();
 
 	return 0;