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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: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt 2011-02-08 13:54:06 -05:00 committed by Steven Rostedt
parent 87d80de280
commit 6752ab4a9c
2 changed files with 23 additions and 19 deletions
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38
Documentation/trace/ftrace.txt
View File

@ -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
#

4
kernel/trace/trace.c
View File

@ -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)