From: Stephen Hemminger <shemminger@xxxxxxxxxx>
Keep track of the number of pages sent over transmit and stop
before going over.
Signed-off-by: Stephen Hemminger <shemminger@xxxxxxxxxx>
Acked-by: Hank Janssen <hjanssen@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/staging/hv/netvsc_drv.c | 72 ++++++++++++++------------------------
1 files changed, 27 insertions(+), 45 deletions(-)
diff --git a/drivers/staging/hv/netvsc_drv.c b/drivers/staging/hv/netvsc_drv.c
index 4124979..a6ca010 100644
--- a/drivers/staging/hv/netvsc_drv.c
+++ b/drivers/staging/hv/netvsc_drv.c
@@ -43,6 +43,7 @@
struct net_device_context {
/* point back to our device context */
struct vm_device *device_ctx;
+ unsigned long avail;
};
struct netvsc_driver_context {
@@ -52,8 +53,10 @@ struct netvsc_driver_context {
struct netvsc_driver drv_obj;
};
-/* Need at least MAX_SKB_FRAGS (18) + 1
- to handle worst case fragmented packet */
+#define PACKET_PAGES_LOWATER 8
+/* Need this many pages to handle worst case fragmented packet */
+#define PACKET_PAGES_HIWATER (MAX_SKB_FRAGS + 2)
+
static int ring_size = roundup_pow_of_two(2*MAX_SKB_FRAGS+1);
module_param(ring_size, int, S_IRUGO);
MODULE_PARM_DESC(ring_size, "Ring buffer size (# of pages)");
@@ -122,14 +125,13 @@ static void netvsc_xmit_completion(void *context)
if (skb) {
struct net_device *net = skb->dev;
- dev_kfree_skb_any(skb);
+ struct net_device_context *net_device_ctx = netdev_priv(net);
+ unsigned int num_pages = skb_shinfo(skb)->nr_frags + 2;
- if (netif_queue_stopped(net)) {
- DPRINT_INFO(NETVSC_DRV, "net device (%p) waking up...",
- net);
+ dev_kfree_skb_any(skb);
- netif_wake_queue(net);
- }
+ if ((net_device_ctx->avail += num_pages) >= PACKET_PAGES_HIWATER)
+ netif_wake_queue(net);
}
DPRINT_EXIT(NETVSC_DRV);
@@ -146,7 +148,6 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
struct hv_netvsc_packet *packet;
int ret;
unsigned int i, num_pages;
- int retries = 0;
DPRINT_ENTER(NETVSC_DRV);
@@ -155,14 +156,20 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
/* Add 1 for skb->data and additional one for RNDIS */
num_pages = skb_shinfo(skb)->nr_frags + 1 + 1;
+ if (num_pages > net_device_ctx->avail)
+ return NETDEV_TX_BUSY;
/* Allocate a netvsc packet based on # of frags. */
packet = kzalloc(sizeof(struct hv_netvsc_packet) +
(num_pages * sizeof(struct hv_page_buffer)) +
net_drv_obj->RequestExtSize, GFP_ATOMIC);
if (!packet) {
+ /* out of memory, silently drop packet */
DPRINT_ERR(NETVSC_DRV, "unable to allocate hv_netvsc_packet");
- return -1;
+
+ dev_kfree_skb(skb);
+ net->stats.tx_dropped++;
+ return NETDEV_TX_OK;
}
packet->Extension = (void *)(unsigned long)packet +
@@ -198,52 +205,26 @@ static int netvsc_start_xmit(struct sk_buff *skb, struct net_device *net)
packet->Completion.Send.SendCompletionContext = packet;
packet->Completion.Send.SendCompletionTid = (unsigned long)skb;
-retry_send:
ret = net_drv_obj->OnSend(&net_device_ctx->device_ctx->device_obj,
packet);
-
if (ret == 0) {
- ret = NETDEV_TX_OK;
net->stats.tx_bytes += skb->len;
net->stats.tx_packets++;
- } else {
- retries++;
- if (retries < 4) {
- DPRINT_ERR(NETVSC_DRV, "unable to send..."
- "retrying %d...", retries);
- udelay(100);
- goto retry_send;
- }
- /* no more room or we are shutting down */
- DPRINT_ERR(NETVSC_DRV, "unable to send (%d)..."
- "marking net device (%p) busy", ret, net);
- DPRINT_INFO(NETVSC_DRV, "net device (%p) stopping", net);
+ DPRINT_DBG(NETVSC_DRV, "# of xmits %lu total size %lu",
+ net->stats.tx_packets,
+ net->stats.tx_bytes);
- ret = NETDEV_TX_BUSY;
+ if ((net_device_ctx->avail -= num_pages) < PACKET_PAGES_LOWATER)
+ netif_stop_queue(net);
+ } else {
+ /* we are shutting down or bus overloaded, just drop packet */
net->stats.tx_dropped++;
-
- netif_stop_queue(net);
-
- /*
- * Null it since the caller will free it instead of the
- * completion routine
- */
- packet->Completion.Send.SendCompletionTid = 0;
-
- /*
- * Release the resources since we will not get any send
- * completion
- */
- netvsc_xmit_completion((void *)packet);
+ netvsc_xmit_completion(packet);
}
- DPRINT_DBG(NETVSC_DRV, "# of xmits %lu total size %lu",
- net->stats.tx_packets,
- net->stats.tx_bytes);
-
DPRINT_EXIT(NETVSC_DRV);
- return ret;
+ return NETDEV_TX_OK;
}
/*
@@ -382,6 +363,7 @@ static int netvsc_probe(struct device *device)
net_device_ctx = netdev_priv(net);
net_device_ctx->device_ctx = device_ctx;
+ net_device_ctx->avail = ring_size;
dev_set_drvdata(device, net);
/* Notify the netvsc driver of the new device */
--
1.7.0.3
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