Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit e9fb2b6d authored by Steven Rostedt's avatar Steven Rostedt
Browse files

tracing: have event_trace_printk use static tracer 



Impact: speed up on event tracing

The event_trace_printk is currently a wrapper function that calls
trace_vprintk. Because it uses a variable for the fmt it misses out
on the optimization of using the binary printk.

This patch makes event_trace_printk into a macro wrapper to use the
fmt as the same as the trace_printks.

Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
parent 82827557

kernel/trace/trace.h

+17 −0
Original line number Diff line number Diff line
@@ -773,4 +773,21 @@ void event_trace_printk(unsigned long ip, const char *fmt, ...); 
extern struct ftrace_event_call __start_ftrace_events[];

extern struct ftrace_event_call __stop_ftrace_events[];



extern const char *__start___trace_bprintk_fmt[];

extern const char *__stop___trace_bprintk_fmt[];



#define event_trace_printk(ip, fmt, args...)				\

do {									\

	__trace_printk_check_format(fmt, ##args);			\

	tracing_record_cmdline(current);				\

	if (__builtin_constant_p(fmt)) {				\

		static const char *trace_printk_fmt			\

		  __attribute__((section("__trace_printk_fmt"))) =	\

			__builtin_constant_p(fmt) ? fmt : NULL;		\

									\

		__trace_bprintk(ip, trace_printk_fmt, ##args);		\

	} else								\

		__trace_printk(ip, fmt, ##args);			\

} while (0)



#endif /* _LINUX_KERNEL_TRACE_H */

kernel/trace/trace_events.c

+0 −10
Original line number Diff line number Diff line
@@ -24,16 +24,6 @@ static DEFINE_MUTEX(event_mutex); 
	     (unsigned long)event < (unsigned long)__stop_ftrace_events; \

	     event++)



void event_trace_printk(unsigned long ip, const char *fmt, ...)

{

	va_list ap;



	va_start(ap, fmt);

	tracing_record_cmdline(current);

	trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap);

	va_end(ap);

}



static void ftrace_clear_events(void)

{

	struct ftrace_event_call *call = (void *)__start_ftrace_events;