From: Lecopzer Chen <[email protected]>
After following the document step by step, the `cat trace` can't be
worked without enabling tracing_on and might mislead newbies about
the functionality.
Signed-off-by: Lecopzer Chen <[email protected]>
---
Documentation/trace/kprobetrace.rst | 6 ++++++
Documentation/trace/uprobetracer.rst | 7 ++++++-
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/Documentation/trace/kprobetrace.rst b/Documentation/trace/kprobetrace.rst
index 235ce2ab131a..baa3c42ba2f4 100644
--- a/Documentation/trace/kprobetrace.rst
+++ b/Documentation/trace/kprobetrace.rst
@@ -189,6 +189,12 @@ events, you need to enable it.
echo 1 > /sys/kernel/debug/tracing/events/kprobes/myprobe/enable
echo 1 > /sys/kernel/debug/tracing/events/kprobes/myretprobe/enable
+Use the following command to start tracing in an interval.
+::
+ # echo 1 > tracing_on
+ Open something...
+ # echo 0 > tracing_on
+
And you can see the traced information via /sys/kernel/debug/tracing/trace.
::
diff --git a/Documentation/trace/uprobetracer.rst b/Documentation/trace/uprobetracer.rst
index 4346e23e3ae7..0b21305fabdc 100644
--- a/Documentation/trace/uprobetracer.rst
+++ b/Documentation/trace/uprobetracer.rst
@@ -152,10 +152,15 @@ events, you need to enable it by::
# echo 1 > events/uprobes/enable
-Lets disable the event after sleeping for some time.
+Lets start tracing, sleep for some time and stop tracing.
::
+ # echo 1 > tracing_on
# sleep 20
+ # echo 0 > tracing_on
+
+Also, you can disable the event by::
+
# echo 0 > events/uprobes/enable
And you can see the traced information via /sys/kernel/debug/tracing/trace.
--
2.18.0
On Thu, 9 May 2019 18:31:16 +0800
<[email protected]> wrote:
> From: Lecopzer Chen <[email protected]>
>
> After following the document step by step, the `cat trace` can't be
> worked without enabling tracing_on and might mislead newbies about
> the functionality.
OK, but isn't tracing_on enabled by default?
Anyway, it looks good to me (for making sure the trace is enabled).
Acked-by: Masami Hiramatsu <[email protected]>
Thanks!
>
> Signed-off-by: Lecopzer Chen <[email protected]>
> ---
> Documentation/trace/kprobetrace.rst | 6 ++++++
> Documentation/trace/uprobetracer.rst | 7 ++++++-
> 2 files changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/trace/kprobetrace.rst b/Documentation/trace/kprobetrace.rst
> index 235ce2ab131a..baa3c42ba2f4 100644
> --- a/Documentation/trace/kprobetrace.rst
> +++ b/Documentation/trace/kprobetrace.rst
> @@ -189,6 +189,12 @@ events, you need to enable it.
> echo 1 > /sys/kernel/debug/tracing/events/kprobes/myprobe/enable
> echo 1 > /sys/kernel/debug/tracing/events/kprobes/myretprobe/enable
>
> +Use the following command to start tracing in an interval.
> +::
> + # echo 1 > tracing_on
> + Open something...
> + # echo 0 > tracing_on
> +
> And you can see the traced information via /sys/kernel/debug/tracing/trace.
> ::
>
> diff --git a/Documentation/trace/uprobetracer.rst b/Documentation/trace/uprobetracer.rst
> index 4346e23e3ae7..0b21305fabdc 100644
> --- a/Documentation/trace/uprobetracer.rst
> +++ b/Documentation/trace/uprobetracer.rst
> @@ -152,10 +152,15 @@ events, you need to enable it by::
>
> # echo 1 > events/uprobes/enable
>
> -Lets disable the event after sleeping for some time.
> +Lets start tracing, sleep for some time and stop tracing.
> ::
>
> + # echo 1 > tracing_on
> # sleep 20
> + # echo 0 > tracing_on
> +
> +Also, you can disable the event by::
> +
> # echo 0 > events/uprobes/enable
>
> And you can see the traced information via /sys/kernel/debug/tracing/trace.
> --
> 2.18.0
>
--
Masami Hiramatsu <[email protected]>
>> From: Lecopzer Chen <[email protected]>
>>
>> After following the document step by step, the `cat trace` can't be
>> worked without enabling tracing_on and might mislead newbies about
>> the functionality.
> OK, but isn't tracing_on enabled by default?
Yes, but it may be disabled by some distros' init process.
> Anyway, it looks good to me (for making sure the trace is enabled).
> Acked-by: Masami Hiramatsu <[email protected]>
> Thanks!
Thanks a lots for your reply!
On Thu, 9 May 2019 18:31:16 +0800
<[email protected]> wrote:
> From: Lecopzer Chen <[email protected]>
>
> After following the document step by step, the `cat trace` can't be
> worked without enabling tracing_on and might mislead newbies about
> the functionality.
>
> Signed-off-by: Lecopzer Chen <[email protected]>
Applied, thanks.
jon