__run_timers() -- 处理全部超时定时器

时间:2021-11-27 20:03:18
__run_timers() -- 处理全部超时定时器

run_timer_softirq() --> __run_timers()

/usr/src/linux-2.6./kernel/timer.c

static inline void __run_timers(tvec_base_t *base)
{
structtimer_list *timer; spin_lock_irq(&base->lock);
/*处理所有已经超时的定时器*/
while (time_after_eq(jiffies, base->timer_jiffies)) {
structlist_headwork_list;
structlist_head *head = &work_list;
int index = base->timer_jiffies & TVR_MASK; //(0) /*
* Cascade timers:
*/
if (!index &&
(!cascade(base, &base->tv2, INDEX())) &&
(!cascade(base, &base->tv3, INDEX())) &&
!cascade(base, &base->tv4, INDEX()))
cascade(base, &base->tv5, INDEX());
++base->timer_jiffies;
list_replace_init(base->tv1.vec + index, &work_list); //(1)
/*处理base->tv1.vec[index]链表上的所有定时器*/
while (!list_empty(head)) {
void (*fn)(unsigned long);
unsigned long data; timer = list_entry(head->next, structtimer_list, entry);
fn = timer->function;
data = timer->data; set_running_timer(base, timer);
detach_timer(timer, );
spin_unlock_irq(&base->lock);
{
intpreempt_count = preempt_count();
fn(data);//在不带锁的情况下执行定时器函数
if (preempt_count != preempt_count()) {
printk(KERN_WARNING "huh, entered %p "
"with preempt_count %08x, exited"
" with %08x?\n",
fn, preempt_count,
preempt_count());
BUG();
}
}
spin_lock_irq(&base->lock);
}
}
set_running_timer(base, NULL);
spin_unlock_irq(&base->lock);
} ()
TVR_MASK = =
--------------------------------------
#define TVR_MASK (TVR_SIZE - 1)
#define TVR_SIZE (1 << TVR_BITS)
#define TVR_BITS (CONFIG_BASE_SMALL ? 6 : 8) CONFIG_BASE_SMALL= () 根据base->timer_jiffies获取tv1所管理的数组的一个元素 -- 一个定时器队列