Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

torvalds · torvalds · commit 8d71844b5194 · 2014-08-03T09:58:20.000-07:00
Pull timer fixes from Thomas Gleixner:
 "Two fixes in the timer area:
   - a long-standing lock inversion due to a printk
   - suspend-related hrtimer corruption in sched_clock"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timer: Fix lock inversion between hrtimer_bases.lock and scheduler locks
  sched_clock: Avoid corrupting hrtimer tree during suspend
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c
@@ -146,7 +146,8 @@ static int clockevents_increase_min_delta(struct clock_event_device *dev)
 {
 	/* Nothing to do if we already reached the limit */
 	if (dev->min_delta_ns >= MIN_DELTA_LIMIT) {
-		printk(KERN_WARNING "CE: Reprogramming failure. Giving up\n");
+		printk_deferred(KERN_WARNING
+				"CE: Reprogramming failure. Giving up\n");
 		dev->next_event.tv64 = KTIME_MAX;
 		return -ETIME;
 	}
@@ -159,9 +160,10 @@ static int clockevents_increase_min_delta(struct clock_event_device *dev)
 	if (dev->min_delta_ns > MIN_DELTA_LIMIT)
 		dev->min_delta_ns = MIN_DELTA_LIMIT;
 
-	printk(KERN_WARNING "CE: %s increased min_delta_ns to %llu nsec\n",
-	       dev->name ? dev->name : "?",
-	       (unsigned long long) dev->min_delta_ns);
+	printk_deferred(KERN_WARNING
+			"CE: %s increased min_delta_ns to %llu nsec\n",
+			dev->name ? dev->name : "?",
+			(unsigned long long) dev->min_delta_ns);
 	return 0;
 }
 
diff --git a/kernel/time/sched_clock.c b/kernel/time/sched_clock.c
@@ -191,14 +191,16 @@ void __init sched_clock_postinit(void)
 
 static int sched_clock_suspend(void)
 {
-	sched_clock_poll(&sched_clock_timer);
+	update_sched_clock();
+	hrtimer_cancel(&sched_clock_timer);
 	cd.suspended = true;
 	return 0;
 }
 
 static void sched_clock_resume(void)
 {
 	cd.epoch_cyc = read_sched_clock();
+	hrtimer_start(&sched_clock_timer, cd.wrap_kt, HRTIMER_MODE_REL);
 	cd.suspended = false;
 }
 

Original file line number	Diff line number	Diff line change
`@@ -191,14 +191,16 @@ void __init sched_clock_postinit(void)`
`191`	`191`
`192`	`192`	`static int sched_clock_suspend(void)`
`193`	`193`	`{`
`194`		`- sched_clock_poll(&sched_clock_timer);`
	`194`	`+ update_sched_clock();`
	`195`	`+ hrtimer_cancel(&sched_clock_timer);`
`195`	`196`	`cd.suspended = true;`
`196`	`197`	`return 0;`
`197`	`198`	`}`
`198`	`199`
`199`	`200`	`static void sched_clock_resume(void)`
`200`	`201`	`{`
`201`	`202`	`cd.epoch_cyc = read_sched_clock();`
	`203`	`+ hrtimer_start(&sched_clock_timer, cd.wrap_kt, HRTIMER_MODE_REL);`
`202`	`204`	`cd.suspended = false;`
`203`	`205`	`}`
`204`	`206`