Currently, the refill work is a global delayed work for all the receive queues. This commit makes the refill work a per receive queue so that we can manage them separately and avoid further mistakes. It also helps the successfully refilled queue avoid the napi_disable in the global delayed refill work like before.
Signed-off-by: Bui Quang Minh <[email protected]> --- drivers/net/virtio_net.c | 155 ++++++++++++++++++--------------------- 1 file changed, 72 insertions(+), 83 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 1bb3aeca66c6..63126e490bda 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -379,6 +379,15 @@ struct receive_queue { struct xdp_rxq_info xsk_rxq_info; struct xdp_buff **xsk_buffs; + + /* Is delayed refill enabled? */ + bool refill_enabled; + + /* The lock to synchronize the access to refill_enabled */ + spinlock_t refill_lock; + + /* Work struct for delayed refilling if we run low on memory. */ + struct delayed_work refill; }; #define VIRTIO_NET_RSS_MAX_KEY_SIZE 40 @@ -441,9 +450,6 @@ 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 +457,6 @@ 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; @@ -720,18 +720,18 @@ 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) +static void enable_delayed_refill(struct receive_queue *rq) { - spin_lock_bh(&vi->refill_lock); - vi->refill_enabled = true; - spin_unlock_bh(&vi->refill_lock); + spin_lock_bh(&rq->refill_lock); + rq->refill_enabled = true; + spin_unlock_bh(&rq->refill_lock); } -static void disable_delayed_refill(struct virtnet_info *vi) +static void disable_delayed_refill(struct receive_queue *rq) { - spin_lock_bh(&vi->refill_lock); - vi->refill_enabled = false; - spin_unlock_bh(&vi->refill_lock); + spin_lock_bh(&rq->refill_lock); + rq->refill_enabled = false; + spin_unlock_bh(&rq->refill_lock); } static void enable_rx_mode_work(struct virtnet_info *vi) @@ -2950,38 +2950,19 @@ static void virtnet_napi_disable(struct receive_queue *rq) static void refill_work(struct work_struct *work) { - struct virtnet_info *vi = - container_of(work, struct virtnet_info, refill.work); + struct receive_queue *rq = + container_of(work, struct receive_queue, 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); + napi_disable(&rq->napi); + still_empty = !try_fill_recv(rq->vq->vdev->priv, 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); - } + /* 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(&rq->refill, HZ / 2); } static int virtnet_receive_xsk_bufs(struct virtnet_info *vi, @@ -3048,10 +3029,10 @@ static int virtnet_receive(struct receive_queue *rq, int budget, if (rq->vq->num_free > min((unsigned int)budget, virtqueue_get_vring_size(rq->vq)) / 2) { if (!try_fill_recv(vi, rq, GFP_ATOMIC)) { - spin_lock(&vi->refill_lock); - if (vi->refill_enabled) - schedule_delayed_work(&vi->refill, 0); - spin_unlock(&vi->refill_lock); + spin_lock(&rq->refill_lock); + if (rq->refill_enabled) + schedule_delayed_work(&rq->refill, 0); + spin_unlock(&rq->refill_lock); } } @@ -3226,13 +3207,13 @@ 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 (i < vi->curr_queue_pairs) { + enable_delayed_refill(&vi->rq[i]); /* Make sure we have some buffers: if oom use wq. */ if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL)) - schedule_delayed_work(&vi->refill, 0); + schedule_delayed_work(&vi->rq[i].refill, 0); + } err = virtnet_enable_queue_pair(vi, i); if (err < 0) @@ -3251,10 +3232,9 @@ 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--) { + disable_delayed_refill(&vi->rq[i]); + cancel_delayed_work_sync(&vi->rq[i].refill); virtnet_disable_queue_pair(vi, i); virtnet_cancel_dim(vi, &vi->rq[i].dim); } @@ -3447,14 +3427,15 @@ 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++) + for (i = 0; i < vi->max_queue_pairs; i++) { + /* + * Make sure refill_work does not run concurrently to + * avoid napi_disable race which leads to deadlock. + */ + disable_delayed_refill(&vi->rq[i]); + cancel_delayed_work_sync(&vi->rq[i].refill); __virtnet_rx_pause(vi, &vi->rq[i]); + } } static void virtnet_rx_pause(struct virtnet_info *vi, struct receive_queue *rq) @@ -3463,8 +3444,8 @@ 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); + disable_delayed_refill(rq); + cancel_delayed_work_sync(&rq->refill); __virtnet_rx_pause(vi, rq); } @@ -3481,25 +3462,26 @@ static void __virtnet_rx_resume(struct virtnet_info *vi, virtnet_napi_enable(rq); if (schedule_refill) - schedule_delayed_work(&vi->refill, 0); + schedule_delayed_work(&rq->refill, 0); } 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) + if (i < vi->curr_queue_pairs) { + enable_delayed_refill(&vi->rq[i]); __virtnet_rx_resume(vi, &vi->rq[i], true); - else + } else { __virtnet_rx_resume(vi, &vi->rq[i], false); + } } } static void virtnet_rx_resume(struct virtnet_info *vi, struct receive_queue *rq) { - enable_delayed_refill(vi); + enable_delayed_refill(rq); __virtnet_rx_resume(vi, rq, true); } @@ -3830,10 +3812,16 @@ static int virtnet_set_queues(struct virtnet_info *vi, u16 queue_pairs) succ: vi->curr_queue_pairs = queue_pairs; /* virtnet_open() will refill when device is going to up. */ - spin_lock_bh(&vi->refill_lock); - if (dev->flags & IFF_UP && vi->refill_enabled) - schedule_delayed_work(&vi->refill, 0); - spin_unlock_bh(&vi->refill_lock); + if (dev->flags & IFF_UP) { + int i; + + for (i = 0; i < vi->curr_queue_pairs; i++) { + spin_lock_bh(&vi->rq[i].refill_lock); + if (vi->rq[i].refill_enabled) + schedule_delayed_work(&vi->rq[i].refill, 0); + spin_unlock_bh(&vi->rq[i].refill_lock); + } + } return 0; } @@ -3843,10 +3831,6 @@ 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 */ @@ -3857,6 +3841,10 @@ static int virtnet_close(struct net_device *dev) cancel_work_sync(&vi->config_work); for (i = 0; i < vi->max_queue_pairs; i++) { + /* Make sure NAPI doesn't schedule refill work */ + disable_delayed_refill(&vi->rq[i]); + /* Make sure refill_work doesn't re-enable napi! */ + cancel_delayed_work_sync(&vi->rq[i].refill); virtnet_disable_queue_pair(vi, i); virtnet_cancel_dim(vi, &vi->rq[i].dim); } @@ -5802,7 +5790,6 @@ 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)) { @@ -6559,8 +6546,9 @@ 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++) { + INIT_DELAYED_WORK(&vi->rq[i].refill, refill_work); + spin_lock_init(&vi->rq[i].refill_lock); vi->rq[i].pages = NULL; netif_napi_add_config(vi->dev, &vi->rq[i].napi, virtnet_poll, i); @@ -6901,7 +6889,6 @@ 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; @@ -7165,7 +7152,9 @@ 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); + for (i = 0; i < vi->max_queue_pairs; i++) + cancel_delayed_work_sync(&vi->rq[i].refill); + free_receive_page_frags(vi); virtnet_del_vqs(vi); free: -- 2.43.0
