Since 63706172 kthread_stop() is not
afraid of dead kernel threads. So no need to check if a thread is
alive before stopping it. These checks still were racy.
Reported-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NAlexander Gordeev <agordeev@redhat.com>
Link: http://lkml.kernel.org/r/20120309135939.GC2114@dhcp-26-207.brq.redhat.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>