diff options
| -rw-r--r-- | drivers/net/xen-netback/common.h | 6 | ||||
| -rw-r--r-- | drivers/net/xen-netback/interface.c | 37 | ||||
| -rw-r--r-- | drivers/net/xen-netback/netback.c | 23 |
3 files changed, 61 insertions, 5 deletions
diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h index f2f8a02afc36..0355f8767e3b 100644 --- a/drivers/net/xen-netback/common.h +++ b/drivers/net/xen-netback/common.h @@ -148,6 +148,9 @@ struct xenvif { struct xen_netif_rx_back_ring rx; struct sk_buff_head rx_queue; RING_IDX rx_last_skb_slots; + bool rx_queue_purge; + + struct timer_list wake_queue; /* This array is allocated seperately as it is large */ struct gnttab_copy *grant_copy_op; @@ -259,4 +262,7 @@ void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success); extern bool separate_tx_rx_irq; +extern unsigned int rx_drain_timeout_msecs; +extern unsigned int rx_drain_timeout_jiffies; + #endif /* __XEN_NETBACK__COMMON_H__ */ diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index b646039e539b..9cc9f638f442 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -115,6 +115,18 @@ static irqreturn_t xenvif_interrupt(int irq, void *dev_id) return IRQ_HANDLED; } +static void xenvif_wake_queue(unsigned long data) +{ + struct xenvif *vif = (struct xenvif *)data; + + if (netif_queue_stopped(vif->dev)) { + netdev_err(vif->dev, "draining TX queue\n"); + vif->rx_queue_purge = true; + xenvif_kick_thread(vif); + netif_wake_queue(vif->dev); + } +} + static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev) { struct xenvif *vif = netdev_priv(dev); @@ -144,8 +156,13 @@ static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev) * then turn off the queue to give the ring a chance to * drain. */ - if (!xenvif_rx_ring_slots_available(vif, min_slots_needed)) + if (!xenvif_rx_ring_slots_available(vif, min_slots_needed)) { + vif->wake_queue.function = xenvif_wake_queue; + vif->wake_queue.data = (unsigned long)vif; xenvif_stop_queue(vif); + mod_timer(&vif->wake_queue, + jiffies + rx_drain_timeout_jiffies); + } skb_queue_tail(&vif->rx_queue, skb); xenvif_kick_thread(vif); @@ -353,6 +370,8 @@ struct xenvif *xenvif_alloc(struct device *parent, domid_t domid, init_timer(&vif->credit_timeout); vif->credit_window_start = get_jiffies_64(); + init_timer(&vif->wake_queue); + dev->netdev_ops = &xenvif_netdev_ops; dev->hw_features = NETIF_F_SG | NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM | @@ -531,6 +550,7 @@ void xenvif_disconnect(struct xenvif *vif) xenvif_carrier_off(vif); if (vif->task) { + del_timer_sync(&vif->wake_queue); kthread_stop(vif->task); vif->task = NULL; } @@ -556,12 +576,25 @@ void xenvif_disconnect(struct xenvif *vif) void xenvif_free(struct xenvif *vif) { int i, unmap_timeout = 0; + /* Here we want to avoid timeout messages if an skb can be legitimatly + * stucked somewhere else. Realisticly this could be an another vif's + * internal or QDisc queue. That another vif also has this + * rx_drain_timeout_msecs timeout, but the timer only ditches the + * internal queue. After that, the QDisc queue can put in worst case + * XEN_NETIF_RX_RING_SIZE / MAX_SKB_FRAGS skbs into that another vif's + * internal queue, so we need several rounds of such timeouts until we + * can be sure that no another vif should have skb's from us. We are + * not sending more skb's, so newly stucked packets are not interesting + * for us here. + */ + unsigned int worst_case_skb_lifetime = (rx_drain_timeout_msecs/1000) * + DIV_ROUND_UP(XENVIF_QUEUE_LENGTH, (XEN_NETIF_RX_RING_SIZE / MAX_SKB_FRAGS)); for (i = 0; i < MAX_PENDING_REQS; ++i) { if (vif->grant_tx_handle[i] != NETBACK_INVALID_HANDLE) { unmap_timeout++; schedule_timeout(msecs_to_jiffies(1000)); - if (unmap_timeout > 9 && + if (unmap_timeout > worst_case_skb_lifetime && net_ratelimit()) netdev_err(vif->dev, "Page still granted! Index: %x\n", diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 58effc49f526..8518a0d1f6f9 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -55,6 +55,13 @@ bool separate_tx_rx_irq = 1; module_param(separate_tx_rx_irq, bool, 0644); +/* When guest ring is filled up, qdisc queues the packets for us, but we have + * to timeout them, otherwise other guests' packets can get stucked there + */ +unsigned int rx_drain_timeout_msecs = 10000; +module_param(rx_drain_timeout_msecs, uint, 0444); +unsigned int rx_drain_timeout_jiffies; + /* * This is the maximum slots a skb can have. If a guest sends a skb * which exceeds this limit it is considered malicious. @@ -1694,8 +1701,9 @@ void xenvif_idx_unmap(struct xenvif *vif, u16 pending_idx) static inline int rx_work_todo(struct xenvif *vif) { - return !skb_queue_empty(&vif->rx_queue) && - xenvif_rx_ring_slots_available(vif, vif->rx_last_skb_slots); + return (!skb_queue_empty(&vif->rx_queue) && + xenvif_rx_ring_slots_available(vif, vif->rx_last_skb_slots)) || + vif->rx_queue_purge; } static inline int tx_work_todo(struct xenvif *vif) @@ -1782,12 +1790,19 @@ int xenvif_kthread_guest_rx(void *data) if (kthread_should_stop()) break; + if (vif->rx_queue_purge) { + skb_queue_purge(&vif->rx_queue); + vif->rx_queue_purge = false; + } + if (!skb_queue_empty(&vif->rx_queue)) xenvif_rx_action(vif); if (skb_queue_empty(&vif->rx_queue) && - netif_queue_stopped(vif->dev)) + netif_queue_stopped(vif->dev)) { + del_timer_sync(&vif->wake_queue); xenvif_start_queue(vif); + } cond_resched(); } @@ -1838,6 +1853,8 @@ static int __init netback_init(void) if (rc) goto failed_init; + rx_drain_timeout_jiffies = msecs_to_jiffies(rx_drain_timeout_msecs); + return 0; failed_init: |