[patch 4/5] sched: Switch wait_task_inactive to schedule_hrtimeout()

[Thomas Gleixner <tglx@linutronix.de>]

[-- Attachment #1: sched-switch-to-hrtimer-for-wait-task-inactive.patch --]
[-- Type: text/plain, Size: 870 bytes --]

When we force thread hard and soft interrupts the startup of ksoftirqd
would hang in kthread_bind() when wait_task_inactive() calls
schedule_timeout_uninterruptible() because there is no softirq yet
which will wake us up.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 kernel/sched.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Index: linux-2.6-tip/kernel/sched.c
===================================================================
--- linux-2.6-tip.orig/kernel/sched.c
+++ linux-2.6-tip/kernel/sched.c
@@ -2224,7 +2224,10 @@ unsigned long wait_task_inactive(struct 
 		 * yield - it could be a while.
 		 */
 		if (unlikely(on_rq)) {
-			schedule_timeout_uninterruptible(1);
+			ktime_t to = ktime_set(0, NSEC_PER_SEC/HZ);
+
+			set_current_state(TASK_UNINTERRUPTIBLE);
+			schedule_hrtimeout(&to, HRTIMER_MODE_REL);
 			continue;
 		}