linux/include/trace/define_trace.h
Steven Rostedt (VMware) d25e37d89d tracepoint: Optimize using static_call()
Currently the tracepoint site will iterate a vector and issue indirect
calls to however many handlers are registered (ie. the vector is
long).

Using static_call() it is possible to optimize this for the common
case of only having a single handler registered. In this case the
static_call() can directly call this handler. Otherwise, if the vector
is longer than 1, call a function that iterates the whole vector like
the current code.

[peterz: updated to new interface]

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20200818135805.279421092@infradead.org
2020-09-01 09:58:06 +02:00

136 lines
3.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* 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, PARAMS(proto), PARAMS(args))
#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, PARAMS(proto), PARAMS(args))
#undef TRACE_EVENT_FN_COND
#define TRACE_EVENT_FN_COND(name, proto, args, cond, tstruct, \
assign, print, reg, unreg) \
DEFINE_TRACE_FN(name, reg, unreg, PARAMS(proto), PARAMS(args))
#undef TRACE_EVENT_NOP
#define TRACE_EVENT_NOP(name, proto, args, struct, assign, print)
#undef DEFINE_EVENT_NOP
#define DEFINE_EVENT_NOP(template, name, proto, args)
#undef DEFINE_EVENT
#define DEFINE_EVENT(template, name, proto, args) \
DEFINE_TRACE(name, PARAMS(proto), PARAMS(args))
#undef DEFINE_EVENT_FN
#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg) \
DEFINE_TRACE_FN(name, reg, unreg, PARAMS(proto), PARAMS(args))
#undef DEFINE_EVENT_PRINT
#define DEFINE_EVENT_PRINT(template, name, proto, args, print) \
DEFINE_TRACE(name, PARAMS(proto), PARAMS(args))
#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, PARAMS(proto), PARAMS(args))
#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 TRACEPOINTS_ENABLED
#include <trace/trace_events.h>
#include <trace/perf.h>
#include <trace/bpf_probe.h>
#endif
#undef TRACE_EVENT
#undef TRACE_EVENT_FN
#undef TRACE_EVENT_FN_COND
#undef TRACE_EVENT_CONDITION
#undef TRACE_EVENT_NOP
#undef DEFINE_EVENT_NOP
#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 */