The original skb management for netpoll was a mess, it had two queue paths
and a callback. This changes it to have a per-instance transmit queue
and use a tasklet rather than a work queue for the congested case.
Signed-off-by: Stephen Hemminger <[email protected]>
---
drivers/net/netconsole.c | 1
include/linux/netpoll.h | 3 -
net/core/netpoll.c | 123 +++++++++++++++--------------------------------
3 files changed, 42 insertions(+), 85 deletions(-)
--- linux-2.6.orig/drivers/net/netconsole.c 2006-10-16 14:15:01.000000000 -0700
+++ linux-2.6/drivers/net/netconsole.c 2006-10-19 08:28:25.000000000 -0700
@@ -60,7 +60,6 @@
.local_port = 6665,
.remote_port = 6666,
.remote_mac = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
- .drop = netpoll_queue,
};
static int configured = 0;
--- linux-2.6.orig/include/linux/netpoll.h 2006-10-16 14:15:04.000000000 -0700
+++ linux-2.6/include/linux/netpoll.h 2006-10-19 08:28:25.000000000 -0700
@@ -27,11 +27,12 @@
struct netpoll_info {
spinlock_t poll_lock;
int poll_owner;
- int tries;
int rx_flags;
spinlock_t rx_lock;
struct netpoll *rx_np; /* netpoll that registered an rx_hook */
struct sk_buff_head arp_tx; /* list of arp requests to reply to */
+ struct sk_buff_head tx_q;
+ struct tasklet_struct tx_task;
};
void netpoll_poll(struct netpoll *np);
--- linux-2.6.orig/net/core/netpoll.c 2006-10-19 08:28:04.000000000 -0700
+++ linux-2.6/net/core/netpoll.c 2006-10-19 09:47:38.000000000 -0700
@@ -40,10 +40,6 @@
static int nr_skbs;
static struct sk_buff *skbs;
-static DEFINE_SPINLOCK(queue_lock);
-static int queue_depth;
-static struct sk_buff *queue_head, *queue_tail;
-
static atomic_t trapped;
#define NETPOLL_RX_ENABLED 1
@@ -56,49 +52,33 @@
static void zap_completion_queue(void);
static void arp_reply(struct sk_buff *skb);
-static void queue_process(void *p)
+static void netpoll_run(unsigned long arg)
{
- unsigned long flags;
+ struct net_device *dev = (struct net_device *) arg;
+ struct netpoll_info *npinfo = dev->npinfo;
struct sk_buff *skb;
- while (queue_head) {
- spin_lock_irqsave(&queue_lock, flags);
-
- skb = queue_head;
- queue_head = skb->next;
- if (skb == queue_tail)
- queue_head = NULL;
-
- queue_depth--;
-
- spin_unlock_irqrestore(&queue_lock, flags);
+ while ((skb = skb_dequeue(&npinfo->tx_q))) {
+ int rc;
- dev_queue_xmit(skb);
- }
-}
-
-static DECLARE_WORK(send_queue, queue_process, NULL);
+ if (!netif_running(dev) || !netif_device_present(dev)) {
+ __kfree_skb(skb);
+ continue;
+ }
-void netpoll_queue(struct sk_buff *skb)
-{
- unsigned long flags;
+ netif_tx_lock(dev);
+ if (netif_queue_stopped(dev))
+ rc = NETDEV_TX_BUSY;
+ else
+ rc = dev->hard_start_xmit(skb, dev);
+ netif_tx_unlock(dev);
- if (queue_depth == MAX_QUEUE_DEPTH) {
- __kfree_skb(skb);
- return;
+ if (rc != NETDEV_TX_OK) {
+ skb_queue_head(&npinfo->tx_q, skb);
+ tasklet_schedule(&npinfo->tx_task);
+ break;
+ }
}
- WARN_ON(skb->protocol == 0);
-
- spin_lock_irqsave(&queue_lock, flags);
- if (!queue_head)
- queue_head = skb;
- else
- queue_tail->next = skb;
- queue_tail = skb;
- queue_depth++;
- spin_unlock_irqrestore(&queue_lock, flags);
-
- schedule_work(&send_queue);
}
static int checksum_udp(struct sk_buff *skb, struct udphdr *uh,
@@ -232,6 +212,7 @@
static struct sk_buff * find_skb(struct netpoll *np, int len, int reserve)
{
+ int once = 1, count = 0;
unsigned long flags;
struct sk_buff *skb = NULL;
@@ -254,6 +235,11 @@
}
if(!skb) {
+ count++;
+ if (once && (count == 1000000)) {
+ printk("out of netpoll skbs!\n");
+ once = 0;
+ }
netpoll_poll(np);
goto repeat;
}
@@ -265,51 +251,17 @@
static void netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
{
- int status;
- struct netpoll_info *npinfo;
+ struct net_device *dev = np->dev;
+ struct netpoll_info *npinfo = dev->npinfo;
- if (!np || !np->dev || !netif_device_present(np->dev) || !netif_running(np->dev)) {
- __kfree_skb(skb);
- return;
- }
-
- npinfo = np->dev->npinfo;
+ skb_queue_tail(&npinfo->tx_q, skb);
/* avoid recursion */
if (npinfo->poll_owner == smp_processor_id() ||
- np->dev->xmit_lock_owner == smp_processor_id()) {
- if (np->drop)
- np->drop(skb);
- else
- __kfree_skb(skb);
- return;
- }
-
- do {
- npinfo->tries--;
- netif_tx_lock(np->dev);
-
- /*
- * network drivers do not expect to be called if the queue is
- * stopped.
- */
- status = NETDEV_TX_BUSY;
- if (!netif_queue_stopped(np->dev))
- status = np->dev->hard_start_xmit(skb, np->dev);
-
- netif_tx_unlock(np->dev);
-
- /* success */
- if(!status) {
- npinfo->tries = MAX_RETRIES; /* reset */
- return;
- }
-
- /* transmit busy */
- netpoll_poll(np);
- udelay(50);
- } while (npinfo->tries > 0);
- __kfree_skb(skb);
+ dev->xmit_lock_owner == smp_processor_id())
+ tasklet_schedule(&npinfo->tx_task);
+ else
+ netpoll_run((unsigned long) dev);
}
void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
@@ -662,9 +614,10 @@
npinfo->rx_np = NULL;
spin_lock_init(&npinfo->poll_lock);
npinfo->poll_owner = -1;
- npinfo->tries = MAX_RETRIES;
spin_lock_init(&npinfo->rx_lock);
skb_queue_head_init(&npinfo->arp_tx);
+ skb_queue_head_init(&npinfo->tx_q);
+ tasklet_init(&npinfo->tx_task, netpoll_run, (unsigned long) ndev);
} else
npinfo = ndev->npinfo;
@@ -772,6 +725,11 @@
npinfo->rx_np = NULL;
npinfo->rx_flags &= ~NETPOLL_RX_ENABLED;
spin_unlock_irqrestore(&npinfo->rx_lock, flags);
+
+ skb_queue_purge(&npinfo->arp_tx);
+ skb_queue_purge(&npinfo->tx_q);
+
+ tasklet_kill(&npinfo->tx_task);
}
dev_put(np->dev);
}
@@ -799,4 +757,3 @@
EXPORT_SYMBOL(netpoll_cleanup);
EXPORT_SYMBOL(netpoll_send_udp);
EXPORT_SYMBOL(netpoll_poll);
-EXPORT_SYMBOL(netpoll_queue);
--
-
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