diff options
| -rw-r--r-- | drivers/net/xen-netback/common.h | 1 | ||||
| -rw-r--r-- | drivers/net/xen-netback/rx.c | 65 |
2 files changed, 42 insertions, 24 deletions
diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h index 4a16d6e33c09..d9dea4829c86 100644 --- a/drivers/net/xen-netback/common.h +++ b/drivers/net/xen-netback/common.h @@ -203,6 +203,7 @@ struct xenvif_queue { /* Per-queue data for xenvif */ unsigned int rx_queue_max; unsigned int rx_queue_len; unsigned long last_rx_time; + unsigned int rx_slots_needed; bool stalled; struct xenvif_copy_state rx_copy; diff --git a/drivers/net/xen-netback/rx.c b/drivers/net/xen-netback/rx.c index accc991d153f..a8511e27d6c1 100644 --- a/drivers/net/xen-netback/rx.c +++ b/drivers/net/xen-netback/rx.c @@ -33,28 +33,36 @@ #include <xen/xen.h> #include <xen/events.h> -static bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue) +/* + * Update the needed ring page slots for the first SKB queued. + * Note that any call sequence outside the RX thread calling this function + * needs to wake up the RX thread via a call of xenvif_kick_thread() + * afterwards in order to avoid a race with putting the thread to sleep. + */ +static void xenvif_update_needed_slots(struct xenvif_queue *queue, + const struct sk_buff *skb) { - RING_IDX prod, cons; - struct sk_buff *skb; - int needed; - unsigned long flags; - - spin_lock_irqsave(&queue->rx_queue.lock, flags); + unsigned int needed = 0; - skb = skb_peek(&queue->rx_queue); - if (!skb) { - spin_unlock_irqrestore(&queue->rx_queue.lock, flags); - return false; + if (skb) { + needed = DIV_ROUND_UP(skb->len, XEN_PAGE_SIZE); + if (skb_is_gso(skb)) + needed++; + if (skb->sw_hash) + needed++; } - needed = DIV_ROUND_UP(skb->len, XEN_PAGE_SIZE); - if (skb_is_gso(skb)) - needed++; - if (skb->sw_hash) - needed++; + WRITE_ONCE(queue->rx_slots_needed, needed); +} - spin_unlock_irqrestore(&queue->rx_queue.lock, flags); +static bool xenvif_rx_ring_slots_available(struct xenvif_queue *queue) +{ + RING_IDX prod, cons; + unsigned int needed; + + needed = READ_ONCE(queue->rx_slots_needed); + if (!needed) + return false; do { prod = queue->rx.sring->req_prod; @@ -80,6 +88,9 @@ void xenvif_rx_queue_tail(struct xenvif_queue *queue, struct sk_buff *skb) spin_lock_irqsave(&queue->rx_queue.lock, flags); + if (skb_queue_empty(&queue->rx_queue)) + xenvif_update_needed_slots(queue, skb); + __skb_queue_tail(&queue->rx_queue, skb); queue->rx_queue_len += skb->len; @@ -100,6 +111,8 @@ static struct sk_buff *xenvif_rx_dequeue(struct xenvif_queue *queue) skb = __skb_dequeue(&queue->rx_queue); if (skb) { + xenvif_update_needed_slots(queue, skb_peek(&queue->rx_queue)); + queue->rx_queue_len -= skb->len; if (queue->rx_queue_len < queue->rx_queue_max) { struct netdev_queue *txq; @@ -487,27 +500,31 @@ void xenvif_rx_action(struct xenvif_queue *queue) xenvif_rx_copy_flush(queue); } -static bool xenvif_rx_queue_stalled(struct xenvif_queue *queue) +static RING_IDX xenvif_rx_queue_slots(const struct xenvif_queue *queue) { RING_IDX prod, cons; prod = queue->rx.sring->req_prod; cons = queue->rx.req_cons; + return prod - cons; +} + +static bool xenvif_rx_queue_stalled(const struct xenvif_queue *queue) +{ + unsigned int needed = READ_ONCE(queue->rx_slots_needed); + return !queue->stalled && - prod - cons < 1 && + xenvif_rx_queue_slots(queue) < needed && time_after(jiffies, queue->last_rx_time + queue->vif->stall_timeout); } static bool xenvif_rx_queue_ready(struct xenvif_queue *queue) { - RING_IDX prod, cons; - - prod = queue->rx.sring->req_prod; - cons = queue->rx.req_cons; + unsigned int needed = READ_ONCE(queue->rx_slots_needed); - return queue->stalled && prod - cons >= 1; + return queue->stalled && xenvif_rx_queue_slots(queue) >= needed; } bool xenvif_have_rx_work(struct xenvif_queue *queue, bool test_kthread) |