Thread (19 messages) 19 messages, 3 authors, 2026-01-05
STALE152d
Revisions (3)
  1. v1 [diff vs current]
  2. v2 current
  3. v3 [diff vs current]

[PATCH net v2 2/3] virtio-net: remove unused delayed refill worker

From: Bui Quang Minh <hidden>
Date: 2026-01-02 15:20:55
Also in: bpf, lkml, virtualization
Subsystem: networking drivers, the rest, virtio net driver · Maintainers: Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, "Michael S. Tsirkin", Jason Wang

Since we change to retry refilling receive buffer in NAPI poll instead
of delayed worker, remove all unused delayed refill worker code.

Signed-off-by: Bui Quang Minh <redacted>
---
 drivers/net/virtio_net.c | 86 ----------------------------------------
 1 file changed, 86 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index ac514c9383ae..7e77a05b5662 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -441,9 +441,6 @@ struct virtnet_info {
 	/* Packet virtio header size */
 	u8 hdr_len;
 
-	/* Work struct for delayed refilling if we run low on memory. */
-	struct delayed_work refill;
-
 	/* UDP tunnel support */
 	bool tx_tnl;
 
@@ -451,12 +448,6 @@ struct virtnet_info {
 
 	bool rx_tnl_csum;
 
-	/* Is delayed refill enabled? */
-	bool refill_enabled;
-
-	/* The lock to synchronize the access to refill_enabled */
-	spinlock_t refill_lock;
-
 	/* Work struct for config space updates */
 	struct work_struct config_work;
 
@@ -720,20 +711,6 @@ static void virtnet_rq_free_buf(struct virtnet_info *vi,
 		put_page(virt_to_head_page(buf));
 }
 
-static void enable_delayed_refill(struct virtnet_info *vi)
-{
-	spin_lock_bh(&vi->refill_lock);
-	vi->refill_enabled = true;
-	spin_unlock_bh(&vi->refill_lock);
-}
-
-static void disable_delayed_refill(struct virtnet_info *vi)
-{
-	spin_lock_bh(&vi->refill_lock);
-	vi->refill_enabled = false;
-	spin_unlock_bh(&vi->refill_lock);
-}
-
 static void enable_rx_mode_work(struct virtnet_info *vi)
 {
 	rtnl_lock();
@@ -2948,42 +2925,6 @@ static void virtnet_napi_disable(struct receive_queue *rq)
 	napi_disable(napi);
 }
 
-static void refill_work(struct work_struct *work)
-{
-	struct virtnet_info *vi =
-		container_of(work, struct virtnet_info, refill.work);
-	bool still_empty;
-	int i;
-
-	for (i = 0; i < vi->curr_queue_pairs; i++) {
-		struct receive_queue *rq = &vi->rq[i];
-
-		/*
-		 * When queue API support is added in the future and the call
-		 * below becomes napi_disable_locked, this driver will need to
-		 * be refactored.
-		 *
-		 * One possible solution would be to:
-		 *   - cancel refill_work with cancel_delayed_work (note:
-		 *     non-sync)
-		 *   - cancel refill_work with cancel_delayed_work_sync in
-		 *     virtnet_remove after the netdev is unregistered
-		 *   - wrap all of the work in a lock (perhaps the netdev
-		 *     instance lock)
-		 *   - check netif_running() and return early to avoid a race
-		 */
-		napi_disable(&rq->napi);
-		still_empty = !try_fill_recv(vi, rq, GFP_KERNEL);
-		virtnet_napi_do_enable(rq->vq, &rq->napi);
-
-		/* In theory, this can happen: if we don't get any buffers in
-		 * we will *never* try to fill again.
-		 */
-		if (still_empty)
-			schedule_delayed_work(&vi->refill, HZ/2);
-	}
-}
-
 static int virtnet_receive_xsk_bufs(struct virtnet_info *vi,
 				    struct receive_queue *rq,
 				    int budget,
@@ -3222,8 +3163,6 @@ static int virtnet_open(struct net_device *dev)
 	struct virtnet_info *vi = netdev_priv(dev);
 	int i, err;
 
-	enable_delayed_refill(vi);
-
 	for (i = 0; i < vi->max_queue_pairs; i++) {
 		if (i < vi->curr_queue_pairs)
 			/* If this fails, we will retry later in
@@ -3249,9 +3188,6 @@ static int virtnet_open(struct net_device *dev)
 	return 0;
 
 err_enable_qp:
-	disable_delayed_refill(vi);
-	cancel_delayed_work_sync(&vi->refill);
-
 	for (i--; i >= 0; i--) {
 		virtnet_disable_queue_pair(vi, i);
 		virtnet_cancel_dim(vi, &vi->rq[i].dim);
@@ -3445,24 +3381,12 @@ static void virtnet_rx_pause_all(struct virtnet_info *vi)
 {
 	int i;
 
-	/*
-	 * Make sure refill_work does not run concurrently to
-	 * avoid napi_disable race which leads to deadlock.
-	 */
-	disable_delayed_refill(vi);
-	cancel_delayed_work_sync(&vi->refill);
 	for (i = 0; i < vi->max_queue_pairs; i++)
 		__virtnet_rx_pause(vi, &vi->rq[i]);
 }
 
 static void virtnet_rx_pause(struct virtnet_info *vi, struct receive_queue *rq)
 {
-	/*
-	 * Make sure refill_work does not run concurrently to
-	 * avoid napi_disable race which leads to deadlock.
-	 */
-	disable_delayed_refill(vi);
-	cancel_delayed_work_sync(&vi->refill);
 	__virtnet_rx_pause(vi, rq);
 }
 
@@ -3486,7 +3410,6 @@ static void virtnet_rx_resume_all(struct virtnet_info *vi)
 {
 	int i;
 
-	enable_delayed_refill(vi);
 	for (i = 0; i < vi->max_queue_pairs; i++) {
 		if (i < vi->curr_queue_pairs)
 			__virtnet_rx_resume(vi, &vi->rq[i], true);
@@ -3497,7 +3420,6 @@ static void virtnet_rx_resume_all(struct virtnet_info *vi)
 
 static void virtnet_rx_resume(struct virtnet_info *vi, struct receive_queue *rq)
 {
-	enable_delayed_refill(vi);
 	__virtnet_rx_resume(vi, rq, true);
 }
 
@@ -3848,10 +3770,6 @@ static int virtnet_close(struct net_device *dev)
 	struct virtnet_info *vi = netdev_priv(dev);
 	int i;
 
-	/* Make sure NAPI doesn't schedule refill work */
-	disable_delayed_refill(vi);
-	/* Make sure refill_work doesn't re-enable napi! */
-	cancel_delayed_work_sync(&vi->refill);
 	/* Prevent the config change callback from changing carrier
 	 * after close
 	 */
@@ -5807,7 +5725,6 @@ static int virtnet_restore_up(struct virtio_device *vdev)
 
 	virtio_device_ready(vdev);
 
-	enable_delayed_refill(vi);
 	enable_rx_mode_work(vi);
 
 	if (netif_running(vi->dev)) {
@@ -6564,7 +6481,6 @@ static int virtnet_alloc_queues(struct virtnet_info *vi)
 	if (!vi->rq)
 		goto err_rq;
 
-	INIT_DELAYED_WORK(&vi->refill, refill_work);
 	for (i = 0; i < vi->max_queue_pairs; i++) {
 		vi->rq[i].pages = NULL;
 		netif_napi_add_config(vi->dev, &vi->rq[i].napi, virtnet_poll,
@@ -6906,7 +6822,6 @@ static int virtnet_probe(struct virtio_device *vdev)
 
 	INIT_WORK(&vi->config_work, virtnet_config_changed_work);
 	INIT_WORK(&vi->rx_mode_work, virtnet_rx_mode_work);
-	spin_lock_init(&vi->refill_lock);
 
 	if (virtio_has_feature(vdev, VIRTIO_NET_F_MRG_RXBUF)) {
 		vi->mergeable_rx_bufs = true;
@@ -7170,7 +7085,6 @@ static int virtnet_probe(struct virtio_device *vdev)
 	net_failover_destroy(vi->failover);
 free_vqs:
 	virtio_reset_device(vdev);
-	cancel_delayed_work_sync(&vi->refill);
 	free_receive_page_frags(vi);
 	virtnet_del_vqs(vi);
 free:
-- 
2.43.0
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help