On Wed, 29 Apr 2020 19:54:16 +0800
Xiao Yang <yangx...@cn.fujitsu.com> wrote:
> On 2020/4/28 22:45, Steven Rostedt wrote:
> > diff --git a/kernel/trace/preemptirq_delay_test.c
> > b/kernel/trace/preemptirq_delay_test.c
> >> index 1c28ca20e30b..6d9131ae7e8c 100644
> >> --- a/kernel/trace/preemptirq_delay_test.c
> >> +++ b/kernel/trace/preemptirq_delay_test.c
> >> @@ -113,15 +113,27 @@ static int preemptirq_delay_run(void *data)
> >>
> >> for (i = 0; i< s; i++)
> >> (testfuncs[i])(i);
> >> +
> >> + while (!kthread_should_stop()) {
> >> + schedule();
> >> + set_current_state(TASK_INTERRUPTIBLE);
> >> + }
> >> +
> >> + __set_current_state(TASK_RUNNING);
> >> +
> >> return 0;
> >> }
> >>
> Hi Steven,
>
> Thanks for your patch.
>
> I also used the following steps to do test and didn't get any
> warning/panic after applying your patch.
> ---------------------------------
> for i in $(seq 1 100); do modprobe preemptirq_delay_test test_mode=irq
> delay=500000; rmmod preemptirq_delay_test; done
> for i in $(seq 1 100); do modprobe preemptirq_delay_test
> test_mode=preempt delay=500000; rmmod preemptirq_delay_test; done
> ---------------------------------
>
> But I am not sure which fix(from you and Joel) is better.
Mine ;-)
The "kthread_should_stop()" is the normal way to end kernel threads. Using
get/put is not the orthodox way.
-- Steve
