[PATCH v11 06/28] tracing: Add a per-event-trigger 'paused' field

[Tom Zanussi <tom.zanussi@linux.intel.com>]

Add a simple per-trigger 'paused' flag, allowing individual triggers
to pause.  We could leave it to individual triggers that need this
functionality to do it themselves, but we also want to allow other
events to control pausing, so add it to the trigger data.

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
---
 kernel/trace/trace.h                | 1 +
 kernel/trace/trace_events_trigger.c | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 892335a..08d9654 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -1168,6 +1168,7 @@ struct event_trigger_data {
 	struct event_filter __rcu	*filter;
 	char				*filter_str;
 	void				*private_data;
+	bool				paused;
 	struct list_head		list;
 };
 
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index c3abef6..8375d29 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -72,6 +72,8 @@ event_triggers_call(struct trace_event_file *file, void *rec)
 		return tt;
 
 	list_for_each_entry_rcu(data, &file->triggers, list) {
+		if (data->paused)
+			continue;
 		if (!rec) {
 			data->ops->func(data, rec);
 			continue;
@@ -110,6 +112,8 @@ event_triggers_post_call(struct trace_event_file *file,
 	struct event_trigger_data *data;
 
 	list_for_each_entry_rcu(data, &file->triggers, list) {
+		if (data->paused)
+			continue;
 		if (data->cmd_ops->trigger_type & tt)
 			data->ops->func(data, rec);
 	}
-- 
1.9.3