diff options
| -rw-r--r-- | drivers/net/xen-netback/common.h | 5 | ||||
| -rw-r--r-- | drivers/net/xen-netback/interface.c | 56 | ||||
| -rw-r--r-- | drivers/net/xen-netback/netback.c | 26 |
3 files changed, 47 insertions, 40 deletions
diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h index ef3026f46a37..d4eb8d2e9cb7 100644 --- a/drivers/net/xen-netback/common.h +++ b/drivers/net/xen-netback/common.h @@ -165,6 +165,7 @@ struct xenvif_queue { /* Per-queue data for xenvif */ u16 dealloc_ring[MAX_PENDING_REQS]; struct task_struct *dealloc_task; wait_queue_head_t dealloc_wq; + atomic_t inflight_packets; /* Use kthread for guest RX */ struct task_struct *task; @@ -329,4 +330,8 @@ extern unsigned int xenvif_max_queues; extern struct dentry *xen_netback_dbg_root; #endif +void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue, + struct sk_buff *skb); +void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue); + #endif /* __XEN_NETBACK__COMMON_H__ */ diff --git a/drivers/net/xen-netback/interface.c b/drivers/net/xen-netback/interface.c index bfd10cb9c8de..e29e15dca86e 100644 --- a/drivers/net/xen-netback/interface.c +++ b/drivers/net/xen-netback/interface.c @@ -43,6 +43,23 @@ #define XENVIF_QUEUE_LENGTH 32 #define XENVIF_NAPI_WEIGHT 64 +/* This function is used to set SKBTX_DEV_ZEROCOPY as well as + * increasing the inflight counter. We need to increase the inflight + * counter because core driver calls into xenvif_zerocopy_callback + * which calls xenvif_skb_zerocopy_complete. + */ +void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue, + struct sk_buff *skb) +{ + skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; + atomic_inc(&queue->inflight_packets); +} + +void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue) +{ + atomic_dec(&queue->inflight_packets); +} + static inline void xenvif_stop_queue(struct xenvif_queue *queue) { struct net_device *dev = queue->vif->dev; @@ -524,9 +541,6 @@ int xenvif_init_queue(struct xenvif_queue *queue) init_timer(&queue->rx_stalled); - netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll, - XENVIF_NAPI_WEIGHT); - return 0; } @@ -560,6 +574,7 @@ int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref, init_waitqueue_head(&queue->wq); init_waitqueue_head(&queue->dealloc_wq); + atomic_set(&queue->inflight_packets, 0); if (tx_evtchn == rx_evtchn) { /* feature-split-event-channels == 0 */ @@ -614,6 +629,9 @@ int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref, wake_up_process(queue->task); wake_up_process(queue->dealloc_task); + netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll, + XENVIF_NAPI_WEIGHT); + return 0; err_rx_unbind: @@ -642,25 +660,6 @@ void xenvif_carrier_off(struct xenvif *vif) rtnl_unlock(); } -static void xenvif_wait_unmap_timeout(struct xenvif_queue *queue, - unsigned int worst_case_skb_lifetime) -{ - int i, unmap_timeout = 0; - - for (i = 0; i < MAX_PENDING_REQS; ++i) { - if (queue->grant_tx_handle[i] != NETBACK_INVALID_HANDLE) { - unmap_timeout++; - schedule_timeout(msecs_to_jiffies(1000)); - if (unmap_timeout > worst_case_skb_lifetime && - net_ratelimit()) - netdev_err(queue->vif->dev, - "Page still granted! Index: %x\n", - i); - i = -1; - } - } -} - void xenvif_disconnect(struct xenvif *vif) { struct xenvif_queue *queue = NULL; @@ -672,6 +671,8 @@ void xenvif_disconnect(struct xenvif *vif) for (queue_index = 0; queue_index < num_queues; ++queue_index) { queue = &vif->queues[queue_index]; + netif_napi_del(&queue->napi); + if (queue->task) { del_timer_sync(&queue->rx_stalled); kthread_stop(queue->task); @@ -704,7 +705,6 @@ void xenvif_disconnect(struct xenvif *vif) void xenvif_deinit_queue(struct xenvif_queue *queue) { free_xenballooned_pages(MAX_PENDING_REQS, queue->mmap_pages); - netif_napi_del(&queue->napi); } void xenvif_free(struct xenvif *vif) @@ -712,21 +712,11 @@ void xenvif_free(struct xenvif *vif) struct xenvif_queue *queue = NULL; unsigned int num_queues = vif->num_queues; unsigned int queue_index; - /* Here we want to avoid timeout messages if an skb can be legitimately - * stuck somewhere else. Realistically this could be an another vif's - * internal or QDisc queue. That another vif also has this - * rx_drain_timeout_msecs timeout, so give it time to drain out. - * Although if that other guest wakes up just before its timeout happens - * and takes only one skb from QDisc, it can hold onto other skbs for a - * longer period. - */ - unsigned int worst_case_skb_lifetime = (rx_drain_timeout_msecs/1000); unregister_netdev(vif->dev); for (queue_index = 0; queue_index < num_queues; ++queue_index) { queue = &vif->queues[queue_index]; - xenvif_wait_unmap_timeout(queue, worst_case_skb_lifetime); xenvif_deinit_queue(queue); } diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 4734472aa620..08f65996534c 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -1525,10 +1525,12 @@ static int xenvif_handle_frag_list(struct xenvif_queue *queue, struct sk_buff *s /* remove traces of mapped pages and frag_list */ skb_frag_list_init(skb); uarg = skb_shinfo(skb)->destructor_arg; + /* increase inflight counter to offset decrement in callback */ + atomic_inc(&queue->inflight_packets); uarg->callback(uarg, true); skb_shinfo(skb)->destructor_arg = NULL; - skb_shinfo(nskb)->tx_flags |= SKBTX_DEV_ZEROCOPY; + xenvif_skb_zerocopy_prepare(queue, nskb); kfree_skb(nskb); return 0; @@ -1589,7 +1591,7 @@ static int xenvif_tx_submit(struct xenvif_queue *queue) if (net_ratelimit()) netdev_err(queue->vif->dev, "Not enough memory to consolidate frag_list!\n"); - skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; + xenvif_skb_zerocopy_prepare(queue, skb); kfree_skb(skb); continue; } @@ -1609,7 +1611,7 @@ static int xenvif_tx_submit(struct xenvif_queue *queue) "Can't setup checksum in net_tx_action\n"); /* We have to set this flag to trigger the callback */ if (skb_shinfo(skb)->destructor_arg) - skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; + xenvif_skb_zerocopy_prepare(queue, skb); kfree_skb(skb); continue; } @@ -1641,7 +1643,7 @@ static int xenvif_tx_submit(struct xenvif_queue *queue) * skb. E.g. the __pskb_pull_tail earlier can do such thing. */ if (skb_shinfo(skb)->destructor_arg) { - skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY; + xenvif_skb_zerocopy_prepare(queue, skb); queue->stats.tx_zerocopy_sent++; } @@ -1681,6 +1683,7 @@ void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success) queue->stats.tx_zerocopy_success++; else queue->stats.tx_zerocopy_fail++; + xenvif_skb_zerocopy_complete(queue); } static inline void xenvif_tx_dealloc_action(struct xenvif_queue *queue) @@ -2058,15 +2061,24 @@ int xenvif_kthread_guest_rx(void *data) return 0; } +static bool xenvif_dealloc_kthread_should_stop(struct xenvif_queue *queue) +{ + /* Dealloc thread must remain running until all inflight + * packets complete. + */ + return kthread_should_stop() && + !atomic_read(&queue->inflight_packets); +} + int xenvif_dealloc_kthread(void *data) { struct xenvif_queue *queue = data; - while (!kthread_should_stop()) { + for (;;) { wait_event_interruptible(queue->dealloc_wq, tx_dealloc_work_todo(queue) || - kthread_should_stop()); - if (kthread_should_stop()) + xenvif_dealloc_kthread_should_stop(queue)); + if (xenvif_dealloc_kthread_should_stop(queue)) break; xenvif_tx_dealloc_action(queue); |