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Commit 3b8e4273 authored by Li Zefan's avatar Li Zefan Committed by Frederic Weisbecker
Browse files

tracing: Move a printk out of ftrace_raw_reg_event_foo() 



Move the printk from each ftrace_raw_reg_event_foo() to
its caller ftrace_event_enable_disable(). This avoids each
regfunc trace event callbacks to handle a same error report
that can be carried from the caller.

See how much space this saves:

   text    data     bss     dec     hex filename
5345151 1961864 7103260 14410275         dbe223 vmlinux.o.old
5331487 1961864 7103260 14396611         dbacc3 vmlinux.o

Signed-off-by: default avatarLi Zefan <lizf@cn.fujitsu.com>
Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Cc: Jason Baron <jbaron@redhat.com>
LKML-Reference: <4B1DC4AC.802@cn.fujitsu.com>
[start cmdline record before calling regfunc to avoid lost
window of pid to comm resolution]
Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
parent 614a71a2

include/trace/ftrace.h

+2 −14
Original line number Diff line number Diff line
@@ -555,13 +555,7 @@ static void ftrace_profile_disable_##name(struct ftrace_event_call *unused)\ 
 *

 * static int ftrace_reg_event_<call>(struct ftrace_event_call *unused)

 * {

 *	int ret;

 *

 *	ret = register_trace_<call>(ftrace_event_<call>);

 *	if (!ret)

 *		pr_info("event trace: Could not activate trace point "

 *			"probe to  <call>");

 *	return ret;

 *	return register_trace_<call>(ftrace_event_<call>);

 * }

 *

 * static void ftrace_unreg_event_<call>(struct ftrace_event_call *unused)
@@ -710,13 +704,7 @@ static void ftrace_raw_event_##call(proto) \ 
									\

static int ftrace_raw_reg_event_##call(struct ftrace_event_call *unused)\

{									\

	int ret;							\

									\

	ret = register_trace_##call(ftrace_raw_event_##call);		\

	if (ret)							\

		pr_info("event trace: Could not activate trace point "	\

			"probe to %s\n", #call);			\

	return ret;							\

	return register_trace_##call(ftrace_raw_event_##call);		\

}									\

									\

static void ftrace_raw_unreg_event_##call(struct ftrace_event_call *unused)\

kernel/trace/trace_events.c

+15 −5
Original line number Diff line number Diff line
@@ -118,9 +118,11 @@ int trace_event_raw_init(struct ftrace_event_call *call) 
}

EXPORT_SYMBOL_GPL(trace_event_raw_init);



static void ftrace_event_enable_disable(struct ftrace_event_call *call,

static int ftrace_event_enable_disable(struct ftrace_event_call *call,

					int enable)

{

	int ret = 0;



	switch (enable) {

	case 0:

		if (call->enabled) {
@@ -131,12 +133,20 @@ static void ftrace_event_enable_disable(struct ftrace_event_call *call, 
		break;

	case 1:

		if (!call->enabled) {

			call->enabled = 1;

			tracing_start_cmdline_record();

			call->regfunc(call);

			ret = call->regfunc(call);

			if (ret) {

				tracing_stop_cmdline_record();

				pr_info("event trace: Could not enable event "

					"%s\n", call->name);

				break;

			}

			call->enabled = 1;

		}

		break;

	}



	return ret;

}



static void ftrace_clear_events(void)
@@ -415,7 +425,7 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, 
	case 0:

	case 1:

		mutex_lock(&event_mutex);

		ftrace_event_enable_disable(call, val);

		ret = ftrace_event_enable_disable(call, val);

		mutex_unlock(&event_mutex);

		break;
@@ -425,7 +435,7 @@ event_enable_write(struct file *filp, const char __user *ubuf, size_t cnt, 


	*ppos += cnt;



	return cnt;

	return ret ? ret : cnt;

}



static ssize_t

kernel/trace/trace_syscalls.c

+2 −8
Original line number Diff line number Diff line
@@ -325,10 +325,7 @@ int reg_event_syscall_enter(struct ftrace_event_call *call) 
	mutex_lock(&syscall_trace_lock);

	if (!sys_refcount_enter)

		ret = register_trace_sys_enter(ftrace_syscall_enter);

	if (ret) {

		pr_info("event trace: Could not activate"

				"syscall entry trace point");

	} else {

	if (!ret) {

		set_bit(num, enabled_enter_syscalls);

		sys_refcount_enter++;

	}
@@ -362,10 +359,7 @@ int reg_event_syscall_exit(struct ftrace_event_call *call) 
	mutex_lock(&syscall_trace_lock);

	if (!sys_refcount_exit)

		ret = register_trace_sys_exit(ftrace_syscall_exit);

	if (ret) {

		pr_info("event trace: Could not activate"

				"syscall exit trace point");

	} else {

	if (!ret) {

		set_bit(num, enabled_exit_syscalls);

		sys_refcount_exit++;

	}