如何杀死内核模块中的等待队列? [英] How to kill a wait queue in kernel module?
问题描述
我新的内核模块。使用一个等待队列,我阻塞线程,直到缓冲区中有数据。使用 hrtimer
,我会定期唤醒队列中。现在,问题是即使我删除了内核模块,我可以看到这个过程线程1
仍在运行。我认为这个问题是在等待队列永远等待,这个过程来到这里受阻。请帮我,我怎么能杀的等待队列,当我删除我的模块。
无效线程1(无效)
{
而(thread_running){
...
wait_event_interruptible(wait_queue,does_buffer_have_data());
...
}
}
有关在等待常用方式的内核主题:
无效线程1(无效)
{
而(!kthread_should_stop())
{
...
wait_event_interruptible(wait_queue,
does_buffer_have_data()|| kthread_should_stop());
如果(kthread_should_stop())破;
...
}
}无效module_cleanup(无效)
{
kthread_stop(T);
}
功能 kthread_should_stop
检查停止
标志当前线程。
功能 kthread_stop(T)
套停止
标志线 T
,中断而线程完成任何等待这个线程执行,并等待。
请注意,虽然 kthread_stop
中断等待,它的不设置任何未决的信号作为主题。
由于该中断的的等待事件的( wait_event_interruptible
等)不返回 -EINTR
就在 kthread_stop
,但只有重新检查的条件。
所以,如果的等待事件的希望后, kthread_stop
要返回,应该检查停止
标志明确地在条件
I am new to kernel module. Using a wait queue, I am blocking the thread until the buffer has data. Using hrtimer
, I am periodically waking up the queue. Now, the problem is even after I remove the kernel module, I could see that the process "thread1"
is still running. I think the issue is that the wait queue is waiting forever and the process got blocked here. Please help me how can I kill the wait queue when I remove my module.
void thread1(void)
{
while (thread_running) {
...
wait_event_interruptible(wait_queue, does_buffer_have_data());
...
}
}
Common way for wait within kernel thread:
void thread1(void)
{
while(!kthread_should_stop())
{
...
wait_event_interruptible(wait_queue,
does_buffer_have_data() || kthread_should_stop());
if(kthread_should_stop()) break;
...
}
}
void module_cleanup(void)
{
kthread_stop(t);
}
Function kthread_should_stop
checks stop
flag for current thread.
Function kthread_stop(t)
sets stop
flag for thread t
, interrupt any waiting performed by this thread, and waits while the thread is finished.
Note, that while kthread_stop
interrupts waiting, it doesn't set any pending signal for the thread.
Because of that interruptible wait for event (wait_event_interruptible
and so) doesn't return -EINTR
just after kthread_stop
but only rechecks condition.
So, if waiting for event wants to be returned after kthread_stop
, it should check stop
flag explicitely in condition.
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