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| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2015-04-01 14:57:27 -0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2015-04-08 09:39:55 -0400 |
| commit | 889204278ccf98c5c097b1d1ae69babc6a3222fd (patch) | |
| tree | 53778b4af3b5ca401c57bc707f9f5ba838c394e7 | |
| parent | acd388fd3af350ab24c6ab6f19b83fc4a4f3aa60 (diff) | |
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 <masami.hiramatsu.pt@hitachi.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| -rw-r--r-- | samples/trace_events/trace-events-sample.h | 20 |
1 files changed, 19 insertions, 1 deletions
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. |