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-rw-r--r--kernel/time/tick-sched.c19
1 files changed, 15 insertions, 4 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 12a900dbb819..85e05ab98253 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -28,6 +28,8 @@
#include "tick-internal.h"
+#include <trace/events/timer.h>
+
/*
* Per cpu nohz control structure
*/
@@ -153,14 +155,20 @@ static bool can_stop_full_tick(void)
{
WARN_ON_ONCE(!irqs_disabled());
- if (!sched_can_stop_tick())
+ if (!sched_can_stop_tick()) {
+ trace_tick_stop(0, "more than 1 task in runqueue\n");
return false;
+ }
- if (!posix_cpu_timers_can_stop_tick(current))
+ if (!posix_cpu_timers_can_stop_tick(current)) {
+ trace_tick_stop(0, "posix timers running\n");
return false;
+ }
- if (!perf_event_can_stop_tick())
+ if (!perf_event_can_stop_tick()) {
+ trace_tick_stop(0, "perf events running\n");
return false;
+ }
/* sched_clock_tick() needs us? */
#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
@@ -168,8 +176,10 @@ static bool can_stop_full_tick(void)
* TODO: kick full dynticks CPUs when
* sched_clock_stable is set.
*/
- if (!sched_clock_stable)
+ if (!sched_clock_stable) {
+ trace_tick_stop(0, "unstable sched clock\n");
return false;
+ }
#endif
return true;
@@ -631,6 +641,7 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
ts->last_tick = hrtimer_get_expires(&ts->sched_timer);
ts->tick_stopped = 1;
+ trace_tick_stop(1, " ");
}
/*