hrtimer: make the nanosleep() syscall use the per process slack

This patch makes the nanosleep() 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: Arjan van de Ven <arjan@linux.intel.com>

hrtimer: make the nanosleep() syscall use the per process slack
This patch makes the nanosleep() 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: Arjan van de Ven <arjan@linux.intel.com>
Arjan van de Ven
1 parent 96d2ab484e
Showing 1 changed file with 6 additions and 1 deletions Side-by-side Diff
kernel/hrtimer.c
@@ -1563,9 +1563,14 @@
 	struct restart_block *restart;
 	struct hrtimer_sleeper t;
 	int ret = 0;
+	unsigned long slack;
  
+	slack = current->timer_slack_ns;
+	if (rt_task(current))
+		slack = 0;
+
 	hrtimer_init_on_stack(&t.timer, clockid, mode);
-	hrtimer_set_expires(&t.timer, timespec_to_ktime(*rqtp));
+	hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack);
 	if (do_nanosleep(&t, mode))
 		goto out;
...	...	@@ -1563,9 +1563,14 @@
1563	1563	struct restart_block *restart;
1564	1564	struct hrtimer_sleeper t;
1565	1565	int ret = 0;
	1566	+ unsigned long slack;
1566	1567
	1568	+ slack = current->timer_slack_ns;
	1569	+ if (rt_task(current))
	1570	+ slack = 0;
	1571	+
1567	1572	hrtimer_init_on_stack(&t.timer, clockid, mode);
1568		- hrtimer_set_expires(&t.timer, timespec_to_ktime(*rqtp));
	1573	+ hrtimer_set_expires_range_ns(&t.timer, timespec_to_ktime(*rqtp), slack);
1569	1574	if (do_nanosleep(&t, mode))
1570	1575	goto out;
1571	1576