From: Oleg Nesterov kthread() sleeps in TASK_INTERRUPTIBLE state waiting for the first wakeup. In theory, this wakeup may come from freeze_process()->signal_wake_up(), so the task can disappear even before kthread_create() sets its ->comm. Change kthread() to use TASK_UNINTERRUPTIBLE. [akpm@linux-foundation.org: s/BUG_ON/WARN_ON+recover] Signed-off-by: Oleg Nesterov Acked-by: "Eric W. Biederman" Signed-off-by: Rafael J. Wysocki kernel/kthread.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) Index: linux-2.6.22-rc2/kernel/kthread.c =================================================================== --- linux-2.6.22-rc2.orig/kernel/kthread.c +++ linux-2.6.22-rc2/kernel/kthread.c @@ -70,7 +70,7 @@ static int kthread(void *_create) data = create->data; /* OK, tell user we're spawned, wait for stop or wakeup */ - __set_current_state(TASK_INTERRUPTIBLE); + __set_current_state(TASK_UNINTERRUPTIBLE); complete(&create->started); schedule(); @@ -162,7 +162,10 @@ EXPORT_SYMBOL(kthread_create); */ void kthread_bind(struct task_struct *k, unsigned int cpu) { - BUG_ON(k->state != TASK_INTERRUPTIBLE); + if (k->state != TASK_UNINTERRUPTIBLE) { + WARN_ON(1); + return; + } /* Must have done schedule() in kthread() before we set_task_cpu */ wait_task_inactive(k); set_task_cpu(k, cpu);