Commit ae4b748e authored by Arjan van de Ven's avatar Arjan van de Ven
Browse files

hrtimer: make the futex() system call use the per process slack value 



This patch makes the futex() system call use the per process
slack value; with this users are able to externally control existing
applications to reduce the wakeup rate.

Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
parent 3bd01206

kernel/futex.c

+5 −1
Original line number Diff line number Diff line
@@ -1296,10 +1296,14 @@ static int futex_wait(u32 __user *uaddr, struct rw_semaphore *fshared, 
		if (!abs_time)

			schedule();

		else {

			unsigned long slack;

			slack = current->timer_slack_ns;

			if (rt_task(current))

				slack = 0;

			hrtimer_init_on_stack(&t.timer, CLOCK_MONOTONIC,

						HRTIMER_MODE_ABS);

			hrtimer_init_sleeper(&t, current);

			hrtimer_set_expires(&t.timer, *abs_time);

			hrtimer_set_expires_range_ns(&t.timer, *abs_time, slack);



			hrtimer_start_expires(&t.timer, HRTIMER_MODE_ABS);

			if (!hrtimer_active(&t.timer))