From: Steven Rostedt 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: Steven Rostedt --- kernel/trace/trace.h | 17 +++++++++++++++++ kernel/trace/trace_events.c | 10 ---------- 2 files changed, 17 insertions(+), 10 deletions(-) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index cede1ab..35cfa7b 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -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 */ diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index ca624df..238ea95 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -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; -- 1.6.1.3 -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/