Re: Kernel module/kthread question

On 02/01/2012 03:49 PM, Daniel Lezcano wrote:

IMO, you have a race condition with nrunning. What guarantee do you have atomic_dec_and_test is called after atomic_inc ?

Nothing (but I believe ~1s is pretty enough for the kernel thread to get woken up). I also tried to to atomic_inc() at the beginning of test(), like:

... static int test(void *unused) { int i; ktime_t expires = ktime_set(0, NSEC_PER_MSEC);

atomic_inc(&nrunning);

for (i = 0; !kthread_should_stop() && i < loopcount; i++) schedule_hrtimeout_range(&expires, 50000, HRTIMER_MODE_REL);

if (atomic_dec_and_test(&nrunning)) complete(&done); return 0; } ...

Results are the same.

Dmitry