Hi,
On Thu, Mar 06, 2014 at 11:42:49PM +0800, Weinn Jheng wrote:
> In order to reduce the interrupt times in the embedded system,
> a receiving workqueue is introduced.
> This modification also enhanced the overall throughput as the
> benefits of reducing interrupt occurrence.
>
> Signed-off-by: Weinn Jheng <clanlab.proj@xxxxxxxxx>
> Cc: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
> Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Dave, does this look ok from NAPI point of view ?
> Cc: Stephen Hemminger <shemminger@xxxxxxxxxx>
> Cc: Felipe Balbi <balbi@xxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> ---
> Changes for v3:
> - Fix the From: and Signed-off-by: by Greg's remind.
>
> Changes for v2:
> - Remove the whitespace trailer.
> - Reorganize the setup/destroy gether_wq work queue procedure
> into APIs gether_setup and gether_cleanup
>
> drivers/usb/gadget/u_ether.c | 111 +++++++++++++++++++++++++++++--------------
> 1 file changed, 76 insertions(+), 35 deletions(-)
>
> diff --git a/drivers/usb/gadget/u_ether.c b/drivers/usb/gadget/u_ether.c
> index b7d4f82..506f16d 100644
> --- a/drivers/usb/gadget/u_ether.c
> +++ b/drivers/usb/gadget/u_ether.c
> @@ -72,6 +72,7 @@ struct eth_dev {
> struct sk_buff_head *list);
>
> struct work_struct work;
> + struct work_struct rx_work;
>
> unsigned long todo;
> #define WORK_RX_MEMORY 0
> @@ -81,6 +82,8 @@ struct eth_dev {
> u8 dev_mac[ETH_ALEN];
> };
>
> +static struct workqueue_struct *gether_wq;
> +
> /*-------------------------------------------------------------------------*/
>
> #define RX_EXTRA 20 /* bytes guarding against rx overflows */
> @@ -253,18 +256,16 @@ enomem:
> DBG(dev, "rx submit --> %d\n", retval);
> if (skb)
> dev_kfree_skb_any(skb);
> - spin_lock_irqsave(&dev->req_lock, flags);
> - list_add(&req->list, &dev->rx_reqs);
> - spin_unlock_irqrestore(&dev->req_lock, flags);
> }
> return retval;
> }
>
> static void rx_complete(struct usb_ep *ep, struct usb_request *req)
> {
> - struct sk_buff *skb = req->context, *skb2;
> + struct sk_buff *skb = req->context;
> struct eth_dev *dev = ep->driver_data;
> int status = req->status;
> + bool rx_queue = 0;
>
> switch (status) {
>
> @@ -288,30 +289,8 @@ static void rx_complete(struct usb_ep *ep, struct usb_request *req)
> } else {
> skb_queue_tail(&dev->rx_frames, skb);
> }
> - skb = NULL;
> -
> - skb2 = skb_dequeue(&dev->rx_frames);
> - while (skb2) {
> - if (status < 0
> - || ETH_HLEN > skb2->len
> - || skb2->len > VLAN_ETH_FRAME_LEN) {
> - dev->net->stats.rx_errors++;
> - dev->net->stats.rx_length_errors++;
> - DBG(dev, "rx length %d\n", skb2->len);
> - dev_kfree_skb_any(skb2);
> - goto next_frame;
> - }
> - skb2->protocol = eth_type_trans(skb2, dev->net);
> - dev->net->stats.rx_packets++;
> - dev->net->stats.rx_bytes += skb2->len;
> -
> - /* no buffer copies needed, unless hardware can't
> - * use skb buffers.
> - */
> - status = netif_rx(skb2);
> -next_frame:
> - skb2 = skb_dequeue(&dev->rx_frames);
> - }
> + if (!status)
> + rx_queue = 1;
> break;
>
> /* software-driven interface shutdown */
> @@ -334,22 +313,20 @@ quiesce:
> /* FALLTHROUGH */
>
> default:
> + rx_queue = 1;
> + dev_kfree_skb_any(skb);
> dev->net->stats.rx_errors++;
> DBG(dev, "rx status %d\n", status);
> break;
> }
>
> - if (skb)
> - dev_kfree_skb_any(skb);
> - if (!netif_running(dev->net)) {
> clean:
> spin_lock(&dev->req_lock);
> list_add(&req->list, &dev->rx_reqs);
> spin_unlock(&dev->req_lock);
> - req = NULL;
> - }
> - if (req)
> - rx_submit(dev, req, GFP_ATOMIC);
> +
> + if (rx_queue)
> + queue_work(gether_wq, &dev->rx_work);
> }
>
> static int prealloc(struct list_head *list, struct usb_ep *ep, unsigned n)
> @@ -414,16 +391,24 @@ static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
> {
> struct usb_request *req;
> unsigned long flags;
> + int rx_counts = 0;
>
> /* fill unused rxq slots with some skb */
> spin_lock_irqsave(&dev->req_lock, flags);
> while (!list_empty(&dev->rx_reqs)) {
> +
> + if (++rx_counts > qlen(dev->gadget, dev->qmult))
> + break;
> +
> req = container_of(dev->rx_reqs.next,
> struct usb_request, list);
> list_del_init(&req->list);
> spin_unlock_irqrestore(&dev->req_lock, flags);
>
> if (rx_submit(dev, req, gfp_flags) < 0) {
> + spin_lock_irqsave(&dev->req_lock, flags);
> + list_add(&req->list, &dev->rx_reqs);
> + spin_unlock_irqrestore(&dev->req_lock, flags);
> defer_kevent(dev, WORK_RX_MEMORY);
> return;
> }
> @@ -433,6 +418,36 @@ static void rx_fill(struct eth_dev *dev, gfp_t gfp_flags)
> spin_unlock_irqrestore(&dev->req_lock, flags);
> }
>
> +static void gether_rxwork(struct work_struct *work)
> +{
> + struct eth_dev *dev = container_of(work, struct eth_dev, rx_work);
> + struct sk_buff *skb;
> + int status = 0;
> +
> + if (!dev->port_usb)
> + return;
> +
> + while ((skb = skb_dequeue(&dev->rx_frames))) {
> + if (status < 0
> + || ETH_HLEN > skb->len
> + || skb->len > VLAN_ETH_FRAME_LEN) {
> + dev->net->stats.rx_errors++;
> + dev->net->stats.rx_length_errors++;
> + DBG(dev, "rx length %d\n", skb->len);
> + dev_kfree_skb_any(skb);
> + continue;
> + }
> + skb->protocol = eth_type_trans(skb, dev->net);
> + dev->net->stats.rx_packets++;
> + dev->net->stats.rx_bytes += skb->len;
> +
> + status = netif_rx_ni(skb);
> + }
> +
> + if (netif_running(dev->net))
> + rx_fill(dev, GFP_KERNEL);
> +}
> +
> static void eth_work(struct work_struct *work)
> {
> struct eth_dev *dev = container_of(work, struct eth_dev, work);
> @@ -767,10 +782,17 @@ struct eth_dev *gether_setup_name(struct usb_gadget *g,
> if (!net)
> return ERR_PTR(-ENOMEM);
>
> + gether_wq = create_singlethread_workqueue("gether");
> + if (!gether_wq) {
> + pr_err("Cannot initialize work queue\n");
> + return ERR_PTR(-ENOMEM);
> + }
> +
> dev = netdev_priv(net);
> spin_lock_init(&dev->lock);
> spin_lock_init(&dev->req_lock);
> INIT_WORK(&dev->work, eth_work);
> + INIT_WORK(&dev->rx_work, gether_rxwork);
> INIT_LIST_HEAD(&dev->tx_reqs);
> INIT_LIST_HEAD(&dev->rx_reqs);
>
> @@ -829,10 +851,17 @@ struct net_device *gether_setup_name_default(const char *netname)
> if (!net)
> return ERR_PTR(-ENOMEM);
>
> + gether_wq = create_singlethread_workqueue("gether");
> + if (!gether_wq) {
> + pr_err("Cannot initialize work queue\n");
> + return ERR_PTR(-ENOMEM);
> + }
> +
> dev = netdev_priv(net);
> spin_lock_init(&dev->lock);
> spin_lock_init(&dev->req_lock);
> INIT_WORK(&dev->work, eth_work);
> + INIT_WORK(&dev->rx_work, gether_rxwork);
> INIT_LIST_HEAD(&dev->tx_reqs);
> INIT_LIST_HEAD(&dev->rx_reqs);
>
> @@ -1010,6 +1039,11 @@ void gether_cleanup(struct eth_dev *dev)
> if (!dev)
> return;
>
> + if (gether_wq) {
> + flush_work(&dev->rx_work);
> + destroy_workqueue(gether_wq);
> + }
> +
> unregister_netdev(dev->net);
> flush_work(&dev->work);
> free_netdev(dev->net);
> @@ -1113,6 +1147,7 @@ void gether_disconnect(struct gether *link)
> {
> struct eth_dev *dev = link->ioport;
> struct usb_request *req;
> + struct sk_buff *skb;
>
> WARN_ON(!dev);
> if (!dev)
> @@ -1139,6 +1174,12 @@ void gether_disconnect(struct gether *link)
> spin_lock(&dev->req_lock);
> }
> spin_unlock(&dev->req_lock);
> +
> + spin_lock(&dev->rx_frames.lock);
> + while ((skb = __skb_dequeue(&dev->rx_frames)))
> + dev_kfree_skb_any(skb);
> + spin_unlock(&dev->rx_frames.lock);
> +
> link->in_ep->driver_data = NULL;
> link->in_ep->desc = NULL;
>
> --
> 1.9.rc1
>
--
balbi
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