tracing: Move print functions into event class

Currently, every event has its own trace_event structure. This is
fine since the structure is needed anyway. But the print function
structure (trace_event_functions) is now separate. Since the output
of the trace event is done by the class (with the exception of events
defined by DEFINE_EVENT_PRINT), it makes sense to have the class
define the print functions that all events in the class can use.

This makes a bigger deal with the syscall events since all syscall events
use the same class. The savings here is another 30K.

   text	   data	    bss	    dec	    hex	filename
4913961	1088356	 861512	6863829	 68bbd5	vmlinux.orig
4900382	1048964	 861512	6810858	 67ecea	vmlinux.init
4900446	1049028	 861512	6810986	 67ed6a	vmlinux.preprint
4895024	1023812	 861512	6780348	 6775bc	vmlinux.print

To accomplish this, and to let the class know what event is being
printed, the event structure is embedded in the ftrace_event_call
structure. This should not be an issues since the event structure
was created for each event anyway.

Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 4 insertions, 14 deletions

diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index f7256770a20f..a1a86a53bc73 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -120,24 +120,20 @@ struct perf_event_attr;
 
 extern struct ftrace_event_class event_class_syscall_enter;
 extern struct ftrace_event_class event_class_syscall_exit;
+extern struct trace_event_functions enter_syscall_print_funcs;
+extern struct trace_event_functions exit_syscall_print_funcs;
 
 #define SYSCALL_TRACE_ENTER_EVENT(sname)                                \
         static struct syscall_metadata __syscall_meta_##sname;          \
         static struct ftrace_event_call                                 \
         __attribute__((__aligned__(4))) event_enter_##sname;            \
-        static struct trace_event_functions enter_syscall_print_funcs_##sname = { \
-                .trace                  = print_syscall_enter,          \
-        };                                                              \
-        static struct trace_event enter_syscall_print_##sname = {       \
-                .funcs                  = &enter_syscall_print_funcs_##sname, \
-        };                                                              \
         static struct ftrace_event_call __used                          \
           __attribute__((__aligned__(4)))                               \
           __attribute__((section("_ftrace_events")))                    \
           event_enter_##sname = {                                       \
                 .name                   = "sys_enter"#sname,            \
                 .class                  = &event_class_syscall_enter,   \
-                .event                  = &enter_syscall_print_##sname, \
+                .event.funcs            = &enter_syscall_print_funcs,   \
                 .data                   = (void *)&__syscall_meta_##sname,\
         }
 
@@ -145,19 +141,13 @@ extern struct ftrace_event_class event_class_syscall_exit;
         static struct syscall_metadata __syscall_meta_##sname;          \
         static struct ftrace_event_call                                 \
         __attribute__((__aligned__(4))) event_exit_##sname;             \
-        static struct trace_event_functions exit_syscall_print_funcs_##sname = { \
-                .trace                  = print_syscall_exit,           \
-        };                                                              \
-        static struct trace_event exit_syscall_print_##sname = {        \
-                .funcs                  = &exit_syscall_print_funcs_##sname, \
-        };                                                              \
         static struct ftrace_event_call __used                          \
           __attribute__((__aligned__(4)))                               \
           __attribute__((section("_ftrace_events")))                    \
           event_exit_##sname = {                                        \
                 .name                   = "sys_exit"#sname,             \
                 .class                  = &event_class_syscall_exit,    \
-                .event                  = &exit_syscall_print_##sname,  \
+                .event.funcs            = &exit_syscall_print_funcs,    \
                 .data                   = (void *)&__syscall_meta_##sname,\
         }