#define NET_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
#define NET_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
-#define TX_MAX_TARGET min_t(int, NET_TX_RING_SIZE, 256)
+
+/* Minimum number of Rx slots (includes slot for GSO metadata). */
+#define NET_RX_SLOTS_MIN (XEN_NETIF_NR_SLOTS_MIN + 1)
/* Queue name is interface name with "-qNNN" appended */
#define QUEUE_NAME_SIZE (IFNAMSIZ + 6)
struct xen_netif_rx_front_ring rx;
int rx_ring_ref;
- /* Receive-ring batched refills. */
-#define RX_MIN_TARGET 8
-#define RX_DFL_MIN_TARGET 64
-#define RX_MAX_TARGET min_t(int, NET_RX_RING_SIZE, 256)
- unsigned rx_min_target, rx_max_target, rx_target;
- struct sk_buff_head rx_batch;
-
struct timer_list rx_refill_timer;
struct sk_buff *rx_skbs[NET_RX_RING_SIZE];
static int netfront_tx_slot_available(struct netfront_queue *queue)
{
return (queue->tx.req_prod_pvt - queue->tx.rsp_cons) <
- (TX_MAX_TARGET - MAX_SKB_FRAGS - 2);
+ (NET_TX_RING_SIZE - MAX_SKB_FRAGS - 2);
}
static void xennet_maybe_wake_tx(struct netfront_queue *queue)
netif_tx_wake_queue(netdev_get_tx_queue(dev, queue->id));
}
-static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
+
+static struct sk_buff *xennet_alloc_one_rx_buffer(struct netfront_queue *queue)
{
- unsigned short id;
struct sk_buff *skb;
struct page *page;
- int i, batch_target, notify;
- RING_IDX req_prod = queue->rx.req_prod_pvt;
- grant_ref_t ref;
- unsigned long pfn;
- void *vaddr;
- struct xen_netif_rx_request *req;
- if (unlikely(!netif_carrier_ok(queue->info->netdev)))
- return;
+ skb = __netdev_alloc_skb(queue->info->netdev,
+ RX_COPY_THRESHOLD + NET_IP_ALIGN,
+ GFP_ATOMIC | __GFP_NOWARN);
+ if (unlikely(!skb))
+ return NULL;
- /*
- * Allocate skbuffs greedily, even though we batch updates to the
- * receive ring. This creates a less bursty demand on the memory
- * allocator, so should reduce the chance of failed allocation requests
- * both for ourself and for other kernel subsystems.
- */
- batch_target = queue->rx_target - (req_prod - queue->rx.rsp_cons);
- for (i = skb_queue_len(&queue->rx_batch); i < batch_target; i++) {
- skb = __netdev_alloc_skb(queue->info->netdev,
- RX_COPY_THRESHOLD + NET_IP_ALIGN,
- GFP_ATOMIC | __GFP_NOWARN);
- if (unlikely(!skb))
- goto no_skb;
-
- /* Align ip header to a 16 bytes boundary */
- skb_reserve(skb, NET_IP_ALIGN);
-
- page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
- if (!page) {
- kfree_skb(skb);
-no_skb:
- /* Could not allocate any skbuffs. Try again later. */
- mod_timer(&queue->rx_refill_timer,
- jiffies + (HZ/10));
-
- /* Any skbuffs queued for refill? Force them out. */
- if (i != 0)
- goto refill;
- break;
- }
-
- skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
- __skb_queue_tail(&queue->rx_batch, skb);
+ page = alloc_page(GFP_ATOMIC | __GFP_NOWARN);
+ if (!page) {
+ kfree_skb(skb);
+ return NULL;
}
+ skb_add_rx_frag(skb, 0, page, 0, 0, PAGE_SIZE);
+
+ /* Align ip header to a 16 bytes boundary */
+ skb_reserve(skb, NET_IP_ALIGN);
+ skb->dev = queue->info->netdev;
+
+ return skb;
+}
+
- /* Is the batch large enough to be worthwhile? */
- if (i < (queue->rx_target/2)) {
- if (req_prod > queue->rx.sring->req_prod)
- goto push;
+static void xennet_alloc_rx_buffers(struct netfront_queue *queue)
+{
+ RING_IDX req_prod = queue->rx.req_prod_pvt;
+ int notify;
+
+ if (unlikely(!netif_carrier_ok(queue->info->netdev)))
return;
- }
- /* Adjust our fill target if we risked running out of buffers. */
- if (((req_prod - queue->rx.sring->rsp_prod) < (queue->rx_target / 4)) &&
- ((queue->rx_target *= 2) > queue->rx_max_target))
- queue->rx_target = queue->rx_max_target;
+ for (req_prod = queue->rx.req_prod_pvt;
+ req_prod - queue->rx.rsp_cons < NET_RX_RING_SIZE;
+ req_prod++) {
+ struct sk_buff *skb;
+ unsigned short id;
+ grant_ref_t ref;
+ unsigned long pfn;
+ struct xen_netif_rx_request *req;
- refill:
- for (i = 0; ; i++) {
- skb = __skb_dequeue(&queue->rx_batch);
- if (skb == NULL)
+ skb = xennet_alloc_one_rx_buffer(queue);
+ if (!skb)
break;
- skb->dev = queue->info->netdev;
-
- id = xennet_rxidx(req_prod + i);
+ id = xennet_rxidx(req_prod);
BUG_ON(queue->rx_skbs[id]);
queue->rx_skbs[id] = skb;
queue->grant_rx_ref[id] = ref;
pfn = page_to_pfn(skb_frag_page(&skb_shinfo(skb)->frags[0]));
- vaddr = page_address(skb_frag_page(&skb_shinfo(skb)->frags[0]));
- req = RING_GET_REQUEST(&queue->rx, req_prod + i);
+ req = RING_GET_REQUEST(&queue->rx, req_prod);
gnttab_grant_foreign_access_ref(ref,
queue->info->xbdev->otherend_id,
pfn_to_mfn(pfn),
req->gref = ref;
}
+ queue->rx.req_prod_pvt = req_prod;
+
+ /* Not enough requests? Try again later. */
+ if (req_prod - queue->rx.rsp_cons < NET_RX_SLOTS_MIN) {
+ mod_timer(&queue->rx_refill_timer, jiffies + (HZ/10));
+ return;
+ }
+
wmb(); /* barrier so backend seens requests */
- /* Above is a suitable barrier to ensure backend will see requests. */
- queue->rx.req_prod_pvt = req_prod + i;
- push:
RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&queue->rx, notify);
if (notify)
notify_remote_via_irq(queue->rx_irq);
work_done -= handle_incoming_queue(queue, &rxq);
- /* If we get a callback with very few responses, reduce fill target. */
- /* NB. Note exponential increase, linear decrease. */
- if (((queue->rx.req_prod_pvt - queue->rx.sring->rsp_prod) >
- ((3*queue->rx_target) / 4)) &&
- (--queue->rx_target < queue->rx_min_target))
- queue->rx_target = queue->rx_min_target;
-
xennet_alloc_rx_buffers(queue);
if (work_done < budget) {
spin_lock_init(&queue->tx_lock);
spin_lock_init(&queue->rx_lock);
- skb_queue_head_init(&queue->rx_batch);
- queue->rx_target = RX_DFL_MIN_TARGET;
- queue->rx_min_target = RX_DFL_MIN_TARGET;
- queue->rx_max_target = RX_MAX_TARGET;
-
init_timer(&queue->rx_refill_timer);
queue->rx_refill_timer.data = (unsigned long)queue;
queue->rx_refill_timer.function = rx_refill_timeout;
}
/* A grant for every tx ring slot */
- if (gnttab_alloc_grant_references(TX_MAX_TARGET,
+ if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
&queue->gref_tx_head) < 0) {
pr_alert("can't alloc tx grant refs\n");
err = -ENOMEM;
}
/* A grant for every rx ring slot */
- if (gnttab_alloc_grant_references(RX_MAX_TARGET,
+ if (gnttab_alloc_grant_references(NET_RX_RING_SIZE,
&queue->gref_rx_head) < 0) {
pr_alert("can't alloc rx grant refs\n");
err = -ENOMEM;
};
#ifdef CONFIG_SYSFS
-static ssize_t show_rxbuf_min(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct net_device *netdev = to_net_dev(dev);
- struct netfront_info *info = netdev_priv(netdev);
- unsigned int num_queues = netdev->real_num_tx_queues;
-
- if (num_queues)
- return sprintf(buf, "%u\n", info->queues[0].rx_min_target);
- else
- return sprintf(buf, "%u\n", RX_MIN_TARGET);
-}
-
-static ssize_t store_rxbuf_min(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t len)
+static ssize_t show_rxbuf(struct device *dev,
+ struct device_attribute *attr, char *buf)
{
- struct net_device *netdev = to_net_dev(dev);
- struct netfront_info *np = netdev_priv(netdev);
- unsigned int num_queues = netdev->real_num_tx_queues;
- char *endp;
- unsigned long target;
- unsigned int i;
- struct netfront_queue *queue;
-
- if (!capable(CAP_NET_ADMIN))
- return -EPERM;
-
- target = simple_strtoul(buf, &endp, 0);
- if (endp == buf)
- return -EBADMSG;
-
- if (target < RX_MIN_TARGET)
- target = RX_MIN_TARGET;
- if (target > RX_MAX_TARGET)
- target = RX_MAX_TARGET;
-
- for (i = 0; i < num_queues; ++i) {
- queue = &np->queues[i];
- spin_lock_bh(&queue->rx_lock);
- if (target > queue->rx_max_target)
- queue->rx_max_target = target;
- queue->rx_min_target = target;
- if (target > queue->rx_target)
- queue->rx_target = target;
-
- xennet_alloc_rx_buffers(queue);
-
- spin_unlock_bh(&queue->rx_lock);
- }
- return len;
-}
-
-static ssize_t show_rxbuf_max(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct net_device *netdev = to_net_dev(dev);
- struct netfront_info *info = netdev_priv(netdev);
- unsigned int num_queues = netdev->real_num_tx_queues;
-
- if (num_queues)
- return sprintf(buf, "%u\n", info->queues[0].rx_max_target);
- else
- return sprintf(buf, "%u\n", RX_MAX_TARGET);
+ return sprintf(buf, "%lu\n", NET_RX_RING_SIZE);
}
-static ssize_t store_rxbuf_max(struct device *dev,
- struct device_attribute *attr,
- const char *buf, size_t len)
+static ssize_t store_rxbuf(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
{
- struct net_device *netdev = to_net_dev(dev);
- struct netfront_info *np = netdev_priv(netdev);
- unsigned int num_queues = netdev->real_num_tx_queues;
char *endp;
unsigned long target;
- unsigned int i = 0;
- struct netfront_queue *queue = NULL;
if (!capable(CAP_NET_ADMIN))
return -EPERM;
if (endp == buf)
return -EBADMSG;
- if (target < RX_MIN_TARGET)
- target = RX_MIN_TARGET;
- if (target > RX_MAX_TARGET)
- target = RX_MAX_TARGET;
-
- for (i = 0; i < num_queues; ++i) {
- queue = &np->queues[i];
- spin_lock_bh(&queue->rx_lock);
- if (target < queue->rx_min_target)
- queue->rx_min_target = target;
- queue->rx_max_target = target;
- if (target < queue->rx_target)
- queue->rx_target = target;
-
- xennet_alloc_rx_buffers(queue);
+ /* rxbuf_min and rxbuf_max are no longer configurable. */
- spin_unlock_bh(&queue->rx_lock);
- }
return len;
}
-static ssize_t show_rxbuf_cur(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct net_device *netdev = to_net_dev(dev);
- struct netfront_info *info = netdev_priv(netdev);
- unsigned int num_queues = netdev->real_num_tx_queues;
-
- if (num_queues)
- return sprintf(buf, "%u\n", info->queues[0].rx_target);
- else
- return sprintf(buf, "0\n");
-}
-
static struct device_attribute xennet_attrs[] = {
- __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf_min, store_rxbuf_min),
- __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf_max, store_rxbuf_max),
- __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf_cur, NULL),
+ __ATTR(rxbuf_min, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf),
+ __ATTR(rxbuf_max, S_IRUGO|S_IWUSR, show_rxbuf, store_rxbuf),
+ __ATTR(rxbuf_cur, S_IRUGO, show_rxbuf, NULL),
};
static int xennet_sysfs_addif(struct net_device *netdev)
projects / cascardo / linux.git / blobdiff