search for: netif_stop_subqueue

...lt; 2+MAX_SKB_FRAGS) { ---> at this point, skb_xmit_done runs. this does: /* Suppress further interrupts. */ virtqueue_disable_cb(vq); /* We were probably waiting for more output buffers. */ netif_wake_subqueue(vi->dev, vq2txq(vq)); ---> netif_stop_subqueue(dev, qnum); ---> queue is now stopped if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { ----> this re-enables interrupts, after an interrupt skb_xmit_done will run again. /* More just got used, free them then recheck. * */...

...lt; 2+MAX_SKB_FRAGS) { ---> at this point, skb_xmit_done runs. this does: /* Suppress further interrupts. */ virtqueue_disable_cb(vq); /* We were probably waiting for more output buffers. */ netif_wake_subqueue(vi->dev, vq2txq(vq)); ---> netif_stop_subqueue(dev, qnum); ---> queue is now stopped if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { ----> this re-enables interrupts, after an interrupt skb_xmit_done will run again. /* More just got used, free them then recheck. * */...

...able_cb(vq); > > /* We were probably waiting for more output buffers. */ > netif_wake_subqueue(vi->dev, vq2txq(vq)); > ---> > > > Because i use vhost-user(poll mode) with virtio_net so at this time vhost had received all packets. > netif_stop_subqueue(dev, qnum); > > ---> queue is now stopped > > if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { > > ----> this re-enables interrupts, after an interrupt skb_xmit_done > will run again. > Before netif_stop_subqueue called vhost had received...

...able_cb(vq); > > /* We were probably waiting for more output buffers. */ > netif_wake_subqueue(vi->dev, vq2txq(vq)); > ---> > > > Because i use vhost-user(poll mode) with virtio_net so at this time vhost had received all packets. > netif_stop_subqueue(dev, qnum); > > ---> queue is now stopped > > if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { > > ----> this re-enables interrupts, after an interrupt skb_xmit_done > will run again. > Before netif_stop_subqueue called vhost had received...

...rs. */ > > netif_wake_subqueue(vi->dev, vq2txq(vq)); > > ---> > > > > > > > > Because i use vhost-user(poll mode) with virtio_net so at this time vhost > had received all packets. Must likely a vhost-user bug then. > > netif_stop_subqueue(dev, qnum); > > > > ---> queue is now stopped > > > > if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { > > > > ----> this re-enables interrupts, after an interrupt skb_xmit_done > > will run again. > > > > Bef...

...rs. */ > > netif_wake_subqueue(vi->dev, vq2txq(vq)); > > ---> > > > > > > > > Because i use vhost-user(poll mode) with virtio_net so at this time vhost > had received all packets. Must likely a vhost-user bug then. > > netif_stop_subqueue(dev, qnum); > > > > ---> queue is now stopped > > > > if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { > > > > ----> this re-enables interrupts, after an interrupt skb_xmit_done > > will run again. > > > > Bef...

...ueue if running out of space + * instead of forcing queuing layer to requeue the skb + * by returning TX_BUSY (and cause a BUG message). + * Since most packets only take 1 or 2 ring slots + * this means 16 slots are typically wasted. + */ if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { netif_stop_subqueue(dev, qnum); if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {

...ueue if running out of space + * instead of forcing queuing layer to requeue the skb + * by returning TX_BUSY (and cause a BUG message). + * Since most packets only take 1 or 2 ring slots + * this means 16 slots are typically wasted. + */ if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { netif_stop_subqueue(dev, qnum); if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) {

If the queue of xdp xmit is not an independent queue, then when the xdp xmit used all the desc, the xmit from the __dev_queue_xmit() may encounter the following error. net ens4: Unexpected TXQ (0) queue failure: -28 This patch adds a check whether sq is full in XDP Xmit. Thanks. Xuan Zhuo (2): virtio_net: separate the logic of checking whether sq is full virtio_net: add checking sq is full

...gt; - nf_reset(skb); > - > /* Apparently nice girls don't return TX_BUSY; stop the queue > * before it gets out of hand. Naturally, this wastes entries. */ > - if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { > + if (sq->vq->num_free < 2+MAX_SKB_FRAGS) > netif_stop_subqueue(dev, qnum); > - if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { > - /* More just got used, free them then recheck. */ > - free_old_xmit_skbs(sq); > - if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) { > - netif_start_subqueue(dev, qnum); > - virtqueue_disabl...

...gt; - nf_reset(skb); > - > /* Apparently nice girls don't return TX_BUSY; stop the queue > * before it gets out of hand. Naturally, this wastes entries. */ > - if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { > + if (sq->vq->num_free < 2+MAX_SKB_FRAGS) > netif_stop_subqueue(dev, qnum); > - if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { > - /* More just got used, free them then recheck. */ > - free_old_xmit_skbs(sq); > - if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) { > - netif_start_subqueue(dev, qnum); > - virtqueue_disabl...

If the queue of xdp xmit is not an independent queue, then when the xdp xmit used all the desc, the xmit from the __dev_queue_xmit() may encounter the following error. net ens4: Unexpected TXQ (0) queue failure: -28 This patch adds a check whether sq is full in XDP Xmit. Thanks. v1: 1. rename to check_sq_full_and_disable 2. reorder some funcs to avoid declaration Xuan Zhuo (3):

...Tx queue will sleep for a while until >> used index go over event offset. >> >> >> Ok, but what if the backend is almost as fast as guest driver? E.g in >> virtio-net we had: >> >> ??? if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { >> ??? ??? netif_stop_subqueue(dev, qnum); >> ??? ??? if (!use_napi && >> ??? ??? ??? unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { >> ??? ??? ??? /* More just got used, free them then recheck. */ >> ??? ??? ??? free_old_xmit_skbs(sq, false); >> ??? ??? ??? if (sq->vq-&gt...

...e_cb_prepare > > > > > > if we disable the napi_tx, It will only be called when the tx ring > > > buffer is relatively small: > > > virtio_net->start_xmit: > > > if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { > > > netif_stop_subqueue(dev, qnum); > > > if (!use_napi && > > > unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { > > > /* More just got used, free them then recheck. */ > > > free_old_xmit_s...

...* instead of forcing queuing layer to requeue the skb > + * by returning TX_BUSY (and cause a BUG message). > + * Since most packets only take 1 or 2 ring slots > + * this means 16 slots are typically wasted. > + */ > if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { > netif_stop_subqueue(dev, qnum); > if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo at vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html

...* instead of forcing queuing layer to requeue the skb > + * by returning TX_BUSY (and cause a BUG message). > + * Since most packets only take 1 or 2 ring slots > + * this means 16 slots are typically wasted. > + */ > if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { > netif_stop_subqueue(dev, qnum); > if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo at vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html

...tly call virtqueue_enable_cb_delayed > or virtqueue_enable_cb_prepare > > if we disable the napi_tx, It will only be called when the tx ring > buffer is relatively small: > virtio_net->start_xmit: > if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { > netif_stop_subqueue(dev, qnum); > if (!use_napi && > unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { > /* More just got used, free them then recheck. */ > free_old_xmit_skbs(sq, false); >...

...t;vq); - /* Don't wait up for transmitted skbs to be freed. */ - skb_orphan(skb); - nf_reset(skb); - /* Apparently nice girls don't return TX_BUSY; stop the queue * before it gets out of hand. Naturally, this wastes entries. */ if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { netif_stop_subqueue(dev, qnum); if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { /* More just got used, free them then recheck. */ - free_old_xmit_skbs(sq); + free_old_xmit_skbs(sq, qsize); if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) { netif_start_subqueue(dev, qnum); virtqueue_d...

...t;vq); - /* Don't wait up for transmitted skbs to be freed. */ - skb_orphan(skb); - nf_reset(skb); - /* Apparently nice girls don't return TX_BUSY; stop the queue * before it gets out of hand. Naturally, this wastes entries. */ if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { netif_stop_subqueue(dev, qnum); if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { /* More just got used, free them then recheck. */ - free_old_xmit_skbs(sq); + free_old_xmit_skbs(sq, qsize); if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) { netif_start_subqueue(dev, qnum); virtqueue_d...

...is enough for next around xmit. > If backend was slow, most likely Tx queue will sleep for a while until used index go over event offset. Ok, but what if the backend is almost as fast as guest driver? E.g in virtio-net we had: ??? if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { ??? ??? netif_stop_subqueue(dev, qnum); ??? ??? if (!use_napi && ??? ??? ??? unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { ??? ??? ??? /* More just got used, free them then recheck. */ ??? ??? ??? free_old_xmit_skbs(sq, false); ??? ??? ??? if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) { ??? ??? ??? ??...