tracing: Create new DEFINE_EVENT_PRINT

After creating the TRACE_EVENT_TEMPLATE I started to look at other
trace points to see what duplication was made. I noticed that there
are several trace points where they are almost identical except for
the name and the output format. Since TRACE_EVENT_TEMPLATE was successful
in bringing down the size of trace events, I added a DEFINE_EVENT_PRINT.

DEFINE_EVENT_PRINT is used just like DEFINE_EVENT is. That is, the
DEFINE_EVENT_PRINT also uses a TRACE_EVENT_TEMPLATE, but it allows the
developer to overwrite the print format. If there are two or more
TRACE_EVENTS that are identical except for the name and print, then
they can be converted to use a TRACE_EVENT_TEMPLATE. Since the
TRACE_EVENT_TEMPLATE already does the print output, the first trace event
would have its print format held in the TRACE_EVENT_TEMPLATE and
be defined with a DEFINE_EVENT. The rest will use the DEFINE_EVENT_PRINT
and override the print format.

Converting the sched trace points to both DEFINE_EVENT and
DEFINE_EVENT_PRINT. Five were converted to DEFINE_EVENT and two were
converted to DEFINE_EVENT_PRINT.

I was able to get the following:

$ size kernel/sched.o-*
   text	   data	    bss	    dec	    hex	filename
  79299	   6776	   2520	  88595	  15a13	kernel/sched.o-notrace
 101941	  11896	   2584	 116421	  1c6c5	kernel/sched.o-templ
 104779	  11896	   2584	 119259	  1d1db	kernel/sched.o-trace

sched.o-notrace is the scheduler compiled with no trace points.
sched.o-templ is with the use of DEFINE_EVENT and DEFINE_EVENT_PRINT
sched.o-trace is the current trace events.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

3 files changed, 126 insertions, 4 deletions

diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 88a5b5a809ec..7063383cca13 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -283,6 +283,8 @@ static inline void tracepoint_synchronize_unregister(void)
 #define TRACE_EVENT_TEMPLATE(name, proto, args, tstruct, assign, print)
 #define DEFINE_EVENT(template, name, proto, args)               \
         DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
+#define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
+        DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
 
 #define TRACE_EVENT(name, proto, args, struct, assign, print)   \
         DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h
index 244985814a43..5d7d855ae21e 100644
--- a/include/trace/define_trace.h
+++ b/include/trace/define_trace.h
@@ -35,6 +35,10 @@
 #define DEFINE_EVENT(template, name, proto, args) \
         DEFINE_TRACE(name)
 
+#undef DEFINE_EVENT_PRINT
+#define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
+        DEFINE_TRACE(name)
+
 #undef DECLARE_TRACE
 #define DECLARE_TRACE(name, proto, args)        \
         DEFINE_TRACE(name)
@@ -69,6 +73,7 @@
 #undef TRACE_EVENT_FN
 #undef TRACE_EVENT_TEMPLATE
 #undef DEFINE_EVENT
+#undef DEFINE_EVENT_PRINT
 #undef TRACE_HEADER_MULTI_READ
 
 /* Only undef what we defined in this file */
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 2969f65d8002..b0461772bc8d 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -67,6 +67,10 @@
 #define DEFINE_EVENT(template, name, proto, args)       \
         static struct ftrace_event_call event_##name
 
+#undef DEFINE_EVENT_PRINT
+#define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
+        DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
+
 #undef __cpparg
 #define __cpparg(arg...) arg
 
@@ -120,6 +124,10 @@
 #undef DEFINE_EVENT
 #define DEFINE_EVENT(template, name, proto, args)
 
+#undef DEFINE_EVENT_PRINT
+#define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
+        DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
+
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 
 /*
@@ -198,15 +206,28 @@
 #undef TRACE_EVENT_TEMPLATE
 #define TRACE_EVENT_TEMPLATE(call, proto, args, tstruct, func, print)   \
 static int                                                              \
-ftrace_format_##call(struct ftrace_event_call *unused,                  \
-                      struct trace_seq *s)                              \
+ftrace_format_setup_##call(struct ftrace_event_call *unused,            \
+                           struct trace_seq *s)                         \
 {                                                                       \
         struct ftrace_raw_##call field __attribute__((unused));         \
         int ret = 0;                                                    \
                                                                         \
         tstruct;                                                        \
                                                                         \
-        trace_seq_printf(s, "\nprint fmt: " print);                     \
+        return ret;                                                     \
+}                                                                       \
+                                                                        \
+static int                                                              \
+ftrace_format_##call(struct ftrace_event_call *unused,                  \
+                     struct trace_seq *s)                               \
+{                                                                       \
+        int ret = 0;                                                    \
+                                                                        \
+        ret = ftrace_format_setup_##call(unused, s);                    \
+        if (!ret)                                                       \
+                return ret;                                             \
+                                                                        \
+        ret = trace_seq_printf(s, "\nprint fmt: " print);               \
                                                                         \
         return ret;                                                     \
 }
@@ -214,6 +235,23 @@ ftrace_format_##call(struct ftrace_event_call *unused,			\
 #undef DEFINE_EVENT
 #define DEFINE_EVENT(template, name, proto, args)
 
+#undef DEFINE_EVENT_PRINT
+#define DEFINE_EVENT_PRINT(template, name, proto, args, print)          \
+static int                                                              \
+ftrace_format_##name(struct ftrace_event_call *unused,                  \
+                      struct trace_seq *s)                              \
+{                                                                       \
+        int ret = 0;                                                    \
+                                                                        \
+        ret = ftrace_format_setup_##template(unused, s);                \
+        if (!ret)                                                       \
+                return ret;                                             \
+                                                                        \
+        trace_seq_printf(s, "\nprint fmt: " print);                     \
+                                                                        \
+        return ret;                                                     \
+}
+
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 
 /*
@@ -325,6 +363,38 @@ ftrace_raw_output_##name(struct trace_iterator *iter, int flags)	\
                                                #name, iter, flags);     \
 }
 
+#undef DEFINE_EVENT_PRINT
+#define DEFINE_EVENT_PRINT(template, call, proto, args, print)          \
+static enum print_line_t                                                \
+ftrace_raw_output_##call(struct trace_iterator *iter, int flags)        \
+{                                                                       \
+        struct trace_seq *s = &iter->seq;                               \
+        struct ftrace_raw_##template *field;                            \
+        struct trace_entry *entry;                                      \
+        struct trace_seq *p;                                            \
+        int ret;                                                        \
+                                                                        \
+        entry = iter->ent;                                              \
+                                                                        \
+        if (entry->type != event_##call.id) {                           \
+                WARN_ON_ONCE(1);                                        \
+                return TRACE_TYPE_UNHANDLED;                            \
+        }                                                               \
+                                                                        \
+        field = (typeof(field))entry;                                   \
+                                                                        \
+        p = &get_cpu_var(ftrace_event_seq);                             \
+        trace_seq_init(p);                                              \
+        ret = trace_seq_printf(s, "%s: ", #call);                       \
+        if (ret)                                                        \
+                ret = trace_seq_printf(s, print);                       \
+        put_cpu();                                                      \
+        if (!ret)                                                       \
+                return TRACE_TYPE_PARTIAL_LINE;                         \
+                                                                        \
+        return TRACE_TYPE_HANDLED;                                      \
+}
+
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 
 #undef __field_ext
@@ -378,6 +448,10 @@ ftrace_define_fields_##call(struct ftrace_event_call *event_call)	\
 #undef DEFINE_EVENT
 #define DEFINE_EVENT(template, name, proto, args)
 
+#undef DEFINE_EVENT_PRINT
+#define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
+        DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
+
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 
 /*
@@ -422,6 +496,10 @@ static inline int ftrace_get_offsets_##call(				\
 #undef DEFINE_EVENT
 #define DEFINE_EVENT(template, name, proto, args)
 
+#undef DEFINE_EVENT_PRINT
+#define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
+        DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
+
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 
 #ifdef CONFIG_EVENT_PROFILE
@@ -461,6 +539,10 @@ static void ftrace_profile_disable_##name(struct ftrace_event_call *unused)\
         unregister_trace_##name(ftrace_profile_##name);                 \
 }
 
+#undef DEFINE_EVENT_PRINT
+#define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
+        DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
+
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 
 #endif
@@ -674,7 +756,19 @@ static int ftrace_raw_init_event_##call(struct ftrace_event_call *unused)\
         event_##call.id = id;                                           \
         INIT_LIST_HEAD(&event_##call.fields);                           \
         return 0;                                                       \
-}                                                                       \
+}
+
+#undef DEFINE_EVENT_PRINT
+#define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
+        DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
+
+#include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
+
+#undef TRACE_EVENT_TEMPLATE
+#define TRACE_EVENT_TEMPLATE(call, proto, args, tstruct, assign, print)
+
+#undef DEFINE_EVENT
+#define DEFINE_EVENT(template, call, proto, args)                       \
                                                                         \
 static struct ftrace_event_call __used                                  \
 __attribute__((__aligned__(4)))                                         \
@@ -690,6 +784,23 @@ __attribute__((section("_ftrace_events"))) event_##call = {		\
         _TRACE_PROFILE_INIT(call)                                       \
 }
 
+#undef DEFINE_EVENT_PRINT
+#define DEFINE_EVENT_PRINT(template, call, proto, args, print)          \
+                                                                        \
+static struct ftrace_event_call __used                                  \
+__attribute__((__aligned__(4)))                                         \
+__attribute__((section("_ftrace_events"))) event_##call = {             \
+        .name                   = #call,                                \
+        .system                 = __stringify(TRACE_SYSTEM),            \
+        .event                  = &ftrace_event_type_##call,            \
+        .raw_init               = ftrace_raw_init_event_##call,         \
+        .regfunc                = ftrace_raw_reg_event_##call,          \
+        .unregfunc              = ftrace_raw_unreg_event_##call,        \
+        .show_format            = ftrace_format_##call,                 \
+        .define_fields          = ftrace_define_fields_##template,      \
+        _TRACE_PROFILE_INIT(call)                                       \
+}
+
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 
 /*
@@ -854,6 +965,10 @@ static void ftrace_profile_##call(proto)			\
         ftrace_profile_templ_##template(event_call, args);      \
 }
 
+#undef DEFINE_EVENT_PRINT
+#define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
+        DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
+
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 #endif /* CONFIG_EVENT_PROFILE */