From 889204278ccf98c5c097b1d1ae69babc6a3222fd Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 1 Apr 2015 14:57:27 -0400 Subject: tracing: Update trace-event-sample with TRACE_SYSTEM_VAR documentation Add documentation about TRACE_SYSTEM needing to be alpha-numeric or with underscores, and that if it is not, then the use of TRACE_SYSTEM_VAR is required to make something that is. An example of this is shown in samples/trace_events/trace-events-sample.h Link: http://lkml.kernel.org/r/20150403013802.220157513@goodmis.org Reviewed-by: Masami Hiramatsu Tested-by: Masami Hiramatsu Signed-off-by: Steven Rostedt --- samples/trace_events/trace-events-sample.h | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) (limited to 'samples') diff --git a/samples/trace_events/trace-events-sample.h b/samples/trace_events/trace-events-sample.h index a2c8b02b6359..19405f18cc8a 100644 --- a/samples/trace_events/trace-events-sample.h +++ b/samples/trace_events/trace-events-sample.h @@ -22,7 +22,25 @@ * protection, just like TRACE_INCLUDE_FILE. */ #undef TRACE_SYSTEM -#define TRACE_SYSTEM sample +#define TRACE_SYSTEM sample-trace + +/* + * TRACE_SYSTEM is expected to be a C valid variable (alpha-numeric + * and underscore), although it may start with numbers. If for some + * reason it is not, you need to add the following lines: + */ +#undef TRACE_SYSTEM_VAR +#define TRACE_SYSTEM_VAR sample_trace +/* + * But the above is only needed if TRACE_SYSTEM is not alpha-numeric + * and underscored. By default, TRACE_SYSTEM_VAR will be equal to + * TRACE_SYSTEM. As TRACE_SYSTEM_VAR must be alpha-numeric, if + * TRACE_SYSTEM is not, then TRACE_SYSTEM_VAR must be defined with + * only alpha-numeric and underscores. + * + * The TRACE_SYSTEM_VAR is only used internally and not visible to + * user space. + */ /* * Notice that this file is not protected like a normal header. -- cgit v1.2.3-58-ga151