void __qdisc_run(struct Qdisc *q)
{
unsigned long start_time = jiffies;
/*
循环调用qdisc_restart发送数据
这个函数qdisc_restart是真正发送数据包的函数
它从队列上取下一个帧，然后尝试将它发送出去
若发送失败则一般是重新入队。
此函数返回值为：发送成功时返回剩余队列长度
发送失败时返回0（若发送成功且剩余队列长度为0也返回0）
*/
while (qdisc_restart(q)) {
/*
* Postpone processing if
* 1. another process needs the CPU;
* 2. we've been doing it for too long.
*/
if (need_resched() || jiffies != start_time) {
//当需要进行调度或者时间超过了1个时间片的时候就退出循环，退出之前发出软中断请求
__netif_schedule(q);
break;
}
}
clear_bit(__QDISC_STATE_RUNNING, &q->state);
}
void qdisc_run_queues(void)
{
struct Qdisc_head **hp, *h;
hp = &qdisc_head.forw;
while ((h = *hp) != &qdisc_head) {
int res = -1;
struct Qdisc *q = (struct Qdisc*)h;
struct device *dev = q->dev;
while (!dev->tbusy && (res = qdisc_restart(dev)) < 0)
/* NOTHING */;
/* An explanation is necessary here.
qdisc_restart called dev->hard_start_xmit,
if device is virtual, it could trigger one more
dev_queue_xmit and a new device could appear
in the active chain. In this case we cannot unlink
the empty queue, because we lost the back pointer.
No problem, we will unlink it during the next round.
*/
if (res == 0 && *hp == h) {
*hp = h->forw;
h->forw = NULL;
continue;
}
hp = &h->forw;
}
}
void __qdisc_run(struct net_device *dev)
{
do {
if (!qdisc_restart(dev))
break;
} while (!netif_queue_stopped(dev));
clear_bit(__LINK_STATE_QDISC_RUNNING, &dev->state);
}
void __qdisc_run(struct net_device *dev)
{
if (unlikely(dev->qdisc == &noop_qdisc))
goto out;
while (qdisc_restart(dev) < 0 && !netif_queue_stopped(dev))
/* NOTHING */;
out:
clear_bit(__LINK_STATE_QDISC_RUNNING, &dev->state);
}
static void dev_do_watchdog(unsigned long dummy)
{
struct Qdisc_head *h;
for (h = qdisc_head.forw; h != &qdisc_head; h = h->forw) {
struct Qdisc *q = (struct Qdisc*)h;
struct device *dev = q->dev;
if (dev->tbusy && jiffies - q->tx_last > q->tx_timeo)
qdisc_restart(dev);
}
dev_watchdog.expires = jiffies + 5*HZ;
add_timer(&dev_watchdog);
}
void __qdisc_run(struct Qdisc *q)
{
unsigned long start_time = jiffies;
while (qdisc_restart(q)) {
if (need_resched() || jiffies != start_time) {
__netif_schedule(q);
break;
}
}
clear_bit(__QDISC_STATE_RUNNING, &q->state);
}
void __qdisc_run(struct Qdisc *q)
{
unsigned long start_time = jiffies;
while (qdisc_restart(q)) {
/*
* Postpone processing if
* 1. another process needs the CPU;
* 2. we've been doing it for too long.
*/
if (need_resched() || jiffies != start_time) {
__netif_schedule(q);
break;
}
}
clear_bit(__QDISC_STATE_RUNNING, &q->state);
}
void __qdisc_run(struct Qdisc *q)
{
int quota = dev_tx_weight;
int packets;
while (qdisc_restart(q, &packets)) {
/*
* Ordered by possible occurrence: Postpone processing if
* 1. we've exceeded packet quota
* 2. another process needs the CPU;
*/
quota -= packets;
if (quota <= 0 || need_resched()) {
__netif_schedule(q);
break;
}
}
}
void __qdisc_run(struct Qdisc *q)
{
int quota = weight_p;
while (qdisc_restart(q)) {
/*
* Ordered by possible occurrence: Postpone processing if
* 1. we've exceeded packet quota
* 2. another process needs the CPU;
*/
if (--quota <= 0 || need_resched()) {
__netif_schedule(q);
break;
}
}
qdisc_run_end(q);
}
void __qdisc_run(struct Qdisc *q)
{
unsigned long start_time = jiffies;
while (qdisc_restart(q)) {
/*
* Postpone processing if
* 1. another process needs the CPU;
* 2. we've been doing it for too long.
*/
if (need_resched() || jiffies != start_time) {
__netif_schedule(q);
break;
}
}
qdisc_run_end(q);
}
int qdisc_restart1(struct net_device *dev)
{
return qdisc_restart(dev);
}
