rtla: Check for trace off also in the trace instance

With the addition of --trigger option, it is also possible to stop
the trace from the -t tracing instance using the traceoff trigger.

Make rtla tools to check if the trace is stopped also in the trace
instance, stopping the execution of the tool.

Link: https://lkml.kernel.org/r/59fc7c6f23dddd5c8b7ef1782cf3da51ea2ce0f5.1646247211.git.bristot@kernel.org

Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Clark Williams <williams@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/tools/tracing/rtla/src/trace.c b/tools/tracing/rtla/src/trace.c
index 8249ec4d77cc..5784c9f9e570 100644
--- a/tools/tracing/rtla/src/trace.c
+++ b/tools/tracing/rtla/src/trace.c
@@ -516,3 +516,22 @@ void trace_events_destroy(struct trace_instance *instance,
 	trace_events_disable(instance, events);
 	trace_events_free(events);
 }
+
+int trace_is_off(struct trace_instance *tool, struct trace_instance *trace)
+{
+	/*
+	 * The tool instance is always present, it is the one used to collect
+	 * data.
+	 */
+	if (!tracefs_trace_is_on(tool->inst))
+		return 1;
+
+	/*
+	 * The trace instance is only enabled when -t is set. IOW, when the system
+	 * is tracing.
+	 */
+	if (trace && !tracefs_trace_is_on(trace->inst))
+		return 1;
+
+	return 0;
+}