If TRACE_INCLDUE_FILE is defined, <trace/events/TRACE_INCLUDE_FILE.h>
will be included and compiled, otherwise it will be
<trace/events/TRACE_SYSTEM.h>
So TRACE_SYSTEM should be defined outside of #if proctection,
just like TRACE_INCLUDE_FILE.
Imaging this scenario:
#include <trace/events/foo.h>
-> TRACE_SYSTEM == foo
...
#include <trace/events/bar.h>
-> TRACE_SYSTEM == bar
...
#define CREATE_TRACE_POINTS
#include <trace/events/foo.h>
-> TRACE_SYSTEM == bar !!!
and then bar.h will be included and compiled.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <4A5A9CF1.2010007@cn.fujitsu.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
When creating trace events for ftrace, the header file with the TRACE_EVENT
macros must also have a macro called TRACE_SYSTEM. This macro describes
the name of the system the TRACE_EVENTS are defined for. It also doubles
as a way for the define_trace.h file to include the file that included
it.
For example:
in irq.h
#define TRACE_SYSTEM irq
[...]
#include <trace/define_trace.h>
The define_trace will use TRACE_SYSTEM to include irq.h. But if the name
of the trace system does not match the name of the trace header file,
one can override it with:
Which will change define_trace.h to inclued foo_trace.h instead of foo.h
The sample comments this, but people that use the sample code will more
likely use the code and not read the comments. This patch changes the
sample code to use the TRACE_INCLUDE_FILE to better show developers how to
use it.
[ Impact: make sample less confusing to developers ]
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This patch adds a sample to the samples directory on how to create
and use TRACE_EVENT trace points.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Li Zefan