Commit 6752ab4a authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
Browse files

tracing: Deprecate tracing_enabled for tracing_on 



tracing_enabled should not be used, it is heavy weight and does not
do much in helping lower the overhead.

tracing_on should be used instead. Warn users to use tracing_on
when tracing_enabled is used as it will soon be removed from the
tracing directory.

Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 87d80de2

Documentation/trace/ftrace.txt

+19 −19
Original line number Diff line number Diff line
@@ -80,11 +80,11 @@ of ftrace. Here is a list of some of the key files: 
	tracers listed here can be configured by

	echoing their name into current_tracer.



  tracing_enabled:

  tracing_on:



	This sets or displays whether the current_tracer

	is activated and tracing or not. Echo 0 into this

	file to disable the tracer or 1 to enable it.

	This sets or displays whether writing to the trace

	ring buffer is enabled. Echo 0 into this file to disable

	the tracer or 1 to enable it.



  trace:
@@ -497,10 +497,10 @@ an example: 
 # echo irqsoff > current_tracer

 # echo latency-format > trace_options

 # echo 0 > tracing_max_latency

 # echo 1 > tracing_enabled

 # echo 1 > tracing_on

 # ls -ltr

 [...]

 # echo 0 > tracing_enabled

 # echo 0 > tracing_on

 # cat trace

# tracer: irqsoff

#
@@ -605,10 +605,10 @@ is much like the irqsoff tracer. 
 # echo preemptoff > current_tracer

 # echo latency-format > trace_options

 # echo 0 > tracing_max_latency

 # echo 1 > tracing_enabled

 # echo 1 > tracing_on

 # ls -ltr

 [...]

 # echo 0 > tracing_enabled

 # echo 0 > tracing_on

 # cat trace

# tracer: preemptoff

#
@@ -753,10 +753,10 @@ tracers. 
 # echo preemptirqsoff > current_tracer

 # echo latency-format > trace_options

 # echo 0 > tracing_max_latency

 # echo 1 > tracing_enabled

 # echo 1 > tracing_on

 # ls -ltr

 [...]

 # echo 0 > tracing_enabled

 # echo 0 > tracing_on

 # cat trace

# tracer: preemptirqsoff

#
@@ -916,9 +916,9 @@ Instead of performing an 'ls', we will run 'sleep 1' under 
 # echo wakeup > current_tracer

 # echo latency-format > trace_options

 # echo 0 > tracing_max_latency

 # echo 1 > tracing_enabled

 # echo 1 > tracing_on

 # chrt -f 5 sleep 1

 # echo 0 > tracing_enabled

 # echo 0 > tracing_on

 # cat trace

# tracer: wakeup

#
@@ -1030,9 +1030,9 @@ ftrace_enabled is set; otherwise this tracer is a nop. 


 # sysctl kernel.ftrace_enabled=1

 # echo function > current_tracer

 # echo 1 > tracing_enabled

 # echo 1 > tracing_on

 # usleep 1

 # echo 0 > tracing_enabled

 # echo 0 > tracing_on

 # cat trace

# tracer: function

#
@@ -1070,7 +1070,7 @@ int trace_fd; 
[...]

int main(int argc, char *argv[]) {

	[...]

	trace_fd = open(tracing_file("tracing_enabled"), O_WRONLY);

	trace_fd = open(tracing_file("tracing_on"), O_WRONLY);

	[...]

	if (condition_hit()) {

		write(trace_fd, "0", 1);
@@ -1521,9 +1521,9 @@ If I am only interested in sys_nanosleep and hrtimer_interrupt: 
 # echo sys_nanosleep hrtimer_interrupt \

		> set_ftrace_filter

 # echo function > current_tracer

 # echo 1 > tracing_enabled

 # echo 1 > tracing_on

 # usleep 1

 # echo 0 > tracing_enabled

 # echo 0 > tracing_on

 # cat trace

# tracer: ftrace

#
@@ -1769,9 +1769,9 @@ different. The trace is live. 
 # echo function > current_tracer

 # cat trace_pipe > /tmp/trace.out &

[1] 4153

 # echo 1 > tracing_enabled

 # echo 1 > tracing_on

 # usleep 1

 # echo 0 > tracing_enabled

 # echo 0 > tracing_on

 # cat trace

# tracer: function

#

kernel/trace/trace.c

+4 −0
Original line number Diff line number Diff line
@@ -2710,6 +2710,10 @@ tracing_ctrl_write(struct file *filp, const char __user *ubuf, 


	mutex_lock(&trace_types_lock);

	if (tracer_enabled ^ val) {



		/* Only need to warn if this is used to change the state */

		WARN_ONCE(1, "tracing_enabled is deprecated. Use tracing_on");



		if (val) {

			tracer_enabled = 1;

			if (current_trace->start)

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