rtla: Add trace_instance_stop

Support not only turning trace on for the timerlat tracer, but also
turning it off.

This will be used in subsequent patches to stop the timerlat tracer
without also wiping the trace buffer.

Cc: stable@vger.kernel.org
Cc: John Kacur <jkacur@redhat.com>
Cc: Luis Goncalves <lgoncalv@redhat.com>
Cc: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/20250116144931.649593-2-tglozar@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

tools/tracing/rtla/src/trace.c

@@ -196,6 +196,14 @@ int trace_instance_start(struct trace_instance *trace)
 	return tracefs_trace_on(trace->inst);
 }
 
+/*
+ * trace_instance_stop - stop tracing a given rtla instance
+ */
+int trace_instance_stop(struct trace_instance *trace)
+{
+	return tracefs_trace_off(trace->inst);
+}
+
 /*
  * trace_events_free - free a list of trace events
  */

tools/tracing/rtla/src/trace.h

@@ -21,6 +21,7 @@ struct trace_instance {
 
 int trace_instance_init(struct trace_instance *trace, char *tool_name);
 int trace_instance_start(struct trace_instance *trace);
+int trace_instance_stop(struct trace_instance *trace);
 void trace_instance_destroy(struct trace_instance *trace);
 
 struct trace_seq *get_trace_seq(void);