Messages in this thread | | | Date | Wed, 29 Apr 2020 12:31:41 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH] kernel/trace: Stop and wait for kthread on preempt irq module unload |
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On Wed, 29 Apr 2020 19:54:16 +0800 Xiao Yang <yangx.jy@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
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