linux/include/trace/define_trace.h
Steven Rostedt f5abaa1bfc tracing: Add DEFINE_EVENT_FN() macro
Each TRACE_EVENT() adds several helper functions. If two or more trace events
share the same structure and print format, they can also share most of these
helper functions and save a lot of space from duplicate code. This is why the
DECLARE_EVENT_CLASS() and DEFINE_EVENT() were created.

Some events require a trigger to be called at registering and unregistering of
the event and to do so they use TRACE_EVENT_FN().

If multiple events require a trigger, they currently have no choice but to use
TRACE_EVENT_FN() as there's no DEFINE_EVENT_FN() available. This unfortunately
causes a lot of wasted duplicate code created.

By adding a DEFINE_EVENT_FN(), these events can still use a
DECLARE_EVENT_CLASS() and then define their own triggers.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/51C3236C.8030508@hds.com
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2013-06-20 22:24:32 -07:00

119 lines
3.1 KiB
C

/*
* Trace files that want to automate creation of all tracepoints defined
* in their file should include this file. The following are macros that the
* trace file may define:
*
* TRACE_SYSTEM defines the system the tracepoint is for
*
* TRACE_INCLUDE_FILE if the file name is something other than TRACE_SYSTEM.h
* This macro may be defined to tell define_trace.h what file to include.
* Note, leave off the ".h".
*
* TRACE_INCLUDE_PATH if the path is something other than core kernel include/trace
* then this macro can define the path to use. Note, the path is relative to
* define_trace.h, not the file including it. Full path names for out of tree
* modules must be used.
*/
#ifdef CREATE_TRACE_POINTS
/* Prevent recursion */
#undef CREATE_TRACE_POINTS
#include <linux/stringify.h>
#undef TRACE_EVENT
#define TRACE_EVENT(name, proto, args, tstruct, assign, print) \
DEFINE_TRACE(name)
#undef TRACE_EVENT_CONDITION
#define TRACE_EVENT_CONDITION(name, proto, args, cond, tstruct, assign, print) \
TRACE_EVENT(name, \
PARAMS(proto), \
PARAMS(args), \
PARAMS(tstruct), \
PARAMS(assign), \
PARAMS(print))
#undef TRACE_EVENT_FN
#define TRACE_EVENT_FN(name, proto, args, tstruct, \
assign, print, reg, unreg) \
DEFINE_TRACE_FN(name, reg, unreg)
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, name, proto, args) \
DEFINE_TRACE(name)
#undef DEFINE_EVENT_FN
#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg) \
DEFINE_TRACE_FN(name, reg, unreg)
#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
DEFINE_TRACE(name)
#undef DEFINE_EVENT_CONDITION
#define DEFINE_EVENT_CONDITION(template, name, proto, args, cond) \
DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
#undef DECLARE_TRACE
#define DECLARE_TRACE(name, proto, args) \
DEFINE_TRACE(name)
#undef TRACE_INCLUDE
#undef __TRACE_INCLUDE
#ifndef TRACE_INCLUDE_FILE
# define TRACE_INCLUDE_FILE TRACE_SYSTEM
# define UNDEF_TRACE_INCLUDE_FILE
#endif
#ifndef TRACE_INCLUDE_PATH
# define __TRACE_INCLUDE(system) <trace/events/system.h>
# define UNDEF_TRACE_INCLUDE_PATH
#else
# define __TRACE_INCLUDE(system) __stringify(TRACE_INCLUDE_PATH/system.h)
#endif
# define TRACE_INCLUDE(system) __TRACE_INCLUDE(system)
/* Let the trace headers be reread */
#define TRACE_HEADER_MULTI_READ
#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
/* Make all open coded DECLARE_TRACE nops */
#undef DECLARE_TRACE
#define DECLARE_TRACE(name, proto, args)
#ifdef CONFIG_EVENT_TRACING
#include <trace/ftrace.h>
#endif
#undef TRACE_EVENT
#undef TRACE_EVENT_FN
#undef TRACE_EVENT_CONDITION
#undef DECLARE_EVENT_CLASS
#undef DEFINE_EVENT
#undef DEFINE_EVENT_FN
#undef DEFINE_EVENT_PRINT
#undef DEFINE_EVENT_CONDITION
#undef TRACE_HEADER_MULTI_READ
#undef DECLARE_TRACE
/* Only undef what we defined in this file */
#ifdef UNDEF_TRACE_INCLUDE_FILE
# undef TRACE_INCLUDE_FILE
# undef UNDEF_TRACE_INCLUDE_FILE
#endif
#ifdef UNDEF_TRACE_INCLUDE_PATH
# undef TRACE_INCLUDE_PATH
# undef UNDEF_TRACE_INCLUDE_PATH
#endif
/* We may be processing more files */
#define CREATE_TRACE_POINTS
#endif /* CREATE_TRACE_POINTS */