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-rw-r--r--kernel/sched/core.c29
-rw-r--r--kernel/trace/trace_events.c9
2 files changed, 23 insertions, 15 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 8b489fc..d1f7149 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -596,17 +596,8 @@ bool sched_can_stop_tick(struct rq *rq)
return false;
/*
- * FIFO realtime policy runs the highest priority task (after DEADLINE).
- * Other runnable tasks are of a lower priority. The scheduler tick
- * isn't needed.
- */
- fifo_nr_running = rq->rt.rt_nr_running - rq->rt.rr_nr_running;
- if (fifo_nr_running)
- return true;
-
- /*
- * Round-robin realtime tasks time slice with other tasks at the same
- * realtime priority.
+ * If there are more than one RR tasks, we need the tick to effect the
+ * actual RR behaviour.
*/
if (rq->rt.rr_nr_running) {
if (rq->rt.rr_nr_running == 1)
@@ -615,8 +606,20 @@ bool sched_can_stop_tick(struct rq *rq)
return false;
}
- /* Normal multitasking need periodic preemption checks */
- if (rq->cfs.nr_running > 1)
+ /*
+ * If there's no RR tasks, but FIFO tasks, we can skip the tick, no
+ * forced preemption between FIFO tasks.
+ */
+ fifo_nr_running = rq->rt.rt_nr_running - rq->rt.rr_nr_running;
+ if (fifo_nr_running)
+ return true;
+
+ /*
+ * If there are no DL,RR/FIFO tasks, there must only be CFS tasks left;
+ * if there's more than one we need the tick for involuntary
+ * preemption.
+ */
+ if (rq->nr_running > 1)
return false;
return true;
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index ced9630..b7b0760 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -2113,8 +2113,13 @@ event_create_dir(struct dentry *parent, struct trace_event_file *file)
trace_create_file("filter", 0644, file->dir, file,
&ftrace_event_filter_fops);
- trace_create_file("trigger", 0644, file->dir, file,
- &event_trigger_fops);
+ /*
+ * Only event directories that can be enabled should have
+ * triggers.
+ */
+ if (!(call->flags & TRACE_EVENT_FL_IGNORE_ENABLE))
+ trace_create_file("trigger", 0644, file->dir, file,
+ &event_trigger_fops);
trace_create_file("format", 0444, file->dir, call,
&ftrace_event_format_fops);