On Wed, Feb 20, 2013 at 11:59 AM, Srinivas Ganji < [email protected]> wrote:
> > On Tue, Feb 19, 2013 at 5:02 PM, Kevin Wilson <[email protected]> wrote: > >> Hi, >> >> Thanks about the info about ps. >> This raises two new questions: >> 1) The following code is a very basic kernel module (based on my >> previous code, removing somethings). >> I do not understand something: >> I call >> /* sleep for a millisecond */ >> msleep(1); >> printk("calling do_exit\n"); >> msleep(60000); >> >> In my understanding, after 1 millisecond, it should have been >> available to the scheduler, and after returning to the line after >> msleep(1), it should print "calling do_exit". However, >> I see no such log message. Any ideas why ? can something be >> added to enable this ? >> >> 2)How can I create a kernel thread so that it will be in >> TASK_INTERRUPTIBLE state ? there must be a way, >> since I see many kernel threads where ps shows "S" in the >> status coumn. >> >> >> struct task_struct *task; >> >> int thread_function(void *data) >> { >> int exit_sig = SIGKILL; >> >> printk("in %s\n",__func__); >> /* sleep for a millisecond */ >> msleep(1); >> printk("calling do_exit\n"); >> msleep(60000); >> do_exit(exit_sig); >> >> return 0; >> } >> >> static int kernel_init(void) >> { >> printk("in kernel_init\n"); >> task = kthread_create(thread_function,NULL,"MY_KERNEL_THREAD"); >> return 0; >> } >> >> static void kernel_exit(void) >> { >> printk("in kernel_exit\n"); >> kthread_stop(task); >> } >> >> >> module_init(kernel_init); >> module_exit(kernel_exit); >> >> >> rgs >> Kevin >> >> > After creating the kernel thread, you can use wake_up_process(task) call > which will run your thread function. > > Generally, when we create a kernel thread using kthread_create, > the process is created in an unrunnable state. It will not start running until explicitly woken up via wake_up_process(). The kthread_create() followed by wake_up_process() is done by a single call kthread_run(). I hope this helps you. Regards Srinivas G. > > >> _______________________________________________ >> Kernelnewbies mailing list >> [email protected] >> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies >> > >
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