From 46b4f7f5d1f7410de48128540ef2d1aab913a619 Mon Sep 17 00:00:00 2001 From: stephen hemminger Date: Tue, 24 Jan 2017 13:06:11 -0800 Subject: [PATCH] netvsc: eliminate per-device outstanding send counter Since now keep track of per-queue outstanding sends, we can avoid one atomic update by removing no longer needed per-device atomic. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- drivers/net/hyperv/hyperv_net.h | 1 - drivers/net/hyperv/netvsc.c | 48 ++++++++++++------------------- drivers/net/hyperv/rndis_filter.c | 21 ++++++++++++-- 3 files changed, 36 insertions(+), 34 deletions(-) diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h index 757205c9cb93..fec365241f37 100644 --- a/drivers/net/hyperv/hyperv_net.h +++ b/drivers/net/hyperv/hyperv_net.h @@ -729,7 +729,6 @@ struct netvsc_channel { struct netvsc_device { u32 nvsp_version; - atomic_t num_outstanding_sends; wait_queue_head_t wait_drain; bool destroy; diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c index 359e7ef7040b..bd055146f098 100644 --- a/drivers/net/hyperv/netvsc.c +++ b/drivers/net/hyperv/netvsc.c @@ -90,6 +90,16 @@ static void free_netvsc_device(struct netvsc_device *nvdev) kfree(nvdev); } + +static inline bool netvsc_channel_idle(const struct netvsc_device *net_device, + u16 q_idx) +{ + const struct netvsc_channel *nvchan = &net_device->chan_table[q_idx]; + + return atomic_read(&net_device->num_outstanding_recvs) == 0 && + atomic_read(&nvchan->queue_sends) == 0; +} + static struct netvsc_device *get_outbound_net_device(struct hv_device *device) { struct netvsc_device *net_device = hv_device_to_netvsc_device(device); @@ -100,22 +110,6 @@ static struct netvsc_device *get_outbound_net_device(struct hv_device *device) return net_device; } -static struct netvsc_device *get_inbound_net_device(struct hv_device *device) -{ - struct netvsc_device *net_device = hv_device_to_netvsc_device(device); - - if (!net_device) - goto get_in_err; - - if (net_device->destroy && - atomic_read(&net_device->num_outstanding_sends) == 0 && - atomic_read(&net_device->num_outstanding_recvs) == 0) - net_device = NULL; - -get_in_err: - return net_device; -} - static void netvsc_destroy_buf(struct hv_device *device) { struct nvsp_message *revoke_packet; @@ -612,7 +606,6 @@ static void netvsc_send_tx_complete(struct netvsc_device *net_device, struct net_device *ndev = hv_get_drvdata(device); struct net_device_context *net_device_ctx = netdev_priv(ndev); struct vmbus_channel *channel = device->channel; - int num_outstanding_sends; u16 q_idx = 0; int queue_sends; @@ -630,13 +623,10 @@ static void netvsc_send_tx_complete(struct netvsc_device *net_device, dev_consume_skb_any(skb); } - num_outstanding_sends = - atomic_dec_return(&net_device->num_outstanding_sends); - queue_sends = atomic_dec_return(&net_device->chan_table[q_idx].queue_sends); - if (net_device->destroy && num_outstanding_sends == 0) + if (net_device->destroy && queue_sends == 0) wake_up(&net_device->wait_drain); if (netif_tx_queue_stopped(netdev_get_tx_queue(ndev, q_idx)) && @@ -823,15 +813,10 @@ static inline int netvsc_send_pkt( } if (ret == 0) { - atomic_inc(&net_device->num_outstanding_sends); atomic_inc_return(&nvchan->queue_sends); - if (ring_avail < RING_AVAIL_PERCENT_LOWATER) { + if (ring_avail < RING_AVAIL_PERCENT_LOWATER) netif_tx_stop_queue(txq); - - if (atomic_read(&nvchan->queue_sends) < 1) - netif_tx_wake_queue(txq); - } } else if (ret == -EAGAIN) { netif_tx_stop_queue(txq); if (atomic_read(&nvchan->queue_sends) < 1) { @@ -1259,11 +1244,14 @@ void netvsc_channel_cb(void *context) else device = channel->device_obj; - net_device = get_inbound_net_device(device); - if (!net_device) + ndev = hv_get_drvdata(device); + if (unlikely(!ndev)) return; - ndev = hv_get_drvdata(device); + net_device = net_device_to_netvsc_device(ndev); + if (unlikely(net_device->destroy) && + netvsc_channel_idle(net_device, q_idx)) + return; while ((desc = get_next_pkt_raw(channel)) != NULL) { netvsc_process_raw_pkt(device, channel, net_device, diff --git a/drivers/net/hyperv/rndis_filter.c b/drivers/net/hyperv/rndis_filter.c index 70b099a731a9..19356f56b7b1 100644 --- a/drivers/net/hyperv/rndis_filter.c +++ b/drivers/net/hyperv/rndis_filter.c @@ -903,6 +903,23 @@ cleanup: return ret; } +static bool netvsc_device_idle(const struct netvsc_device *nvdev) +{ + int i; + + if (atomic_read(&nvdev->num_outstanding_recvs) > 0) + return false; + + for (i = 0; i < nvdev->num_chn; i++) { + const struct netvsc_channel *nvchan = &nvdev->chan_table[i]; + + if (atomic_read(&nvchan->queue_sends) > 0) + return false; + } + + return true; +} + static void rndis_filter_halt_device(struct rndis_device *dev) { struct rndis_request *request; @@ -933,9 +950,7 @@ cleanup: spin_unlock_irqrestore(&hdev->channel->inbound_lock, flags); /* Wait for all send completions */ - wait_event(nvdev->wait_drain, - atomic_read(&nvdev->num_outstanding_sends) == 0 && - atomic_read(&nvdev->num_outstanding_recvs) == 0); + wait_event(nvdev->wait_drain, netvsc_device_idle(nvdev)); if (request) put_rndis_request(dev, request);