Re: [PATCH v2] Documentation: ftrace: clarify filters with dynamic ftrace and graph

[Jonathan Corbet]

On Fri, 13 Apr 2018 11:54:03 -0400
Steven Rostedt  wrote:

> Jon, you want to take it in your tree?

Sure, I'll grab it.

jon
--
To unsubscribe from this list: send the line "unsubscribe linux-doc" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH v2] Documentation: ftrace: clarify filters with dynamic ftrace and graph

[Steven Rostedt]

On Fri, 13 Apr 2018 17:39:15 +0200
Steffen Maier  wrote:

> I fell into the trap of having set up function tracer with a very
> limited filter and then switched over to function_graph and was
> erroneously wondering why the latter did not trace what I expected,
> which was the full unabridged graph recursion.
> 
> Signed-off-by: Steffen Maier 
> Cc: Steven Rostedt 

Looks good.

Reviewed-by: Steven Rostedt (VMware) 

> Cc: Ingo Molnar 
> Cc: Jonathan Corbet 

Jon, you want to take it in your tree?

-- Steve

> Cc: linux-doc@vger.kernel.org
> ---
> 
> Changes since v1:
> Integrated review comments by Steven Rostedt
> * less emotional phrasing
> * also mention function profiling with set_ftrace_filter
>   (hopefully I got that right as I don't have experience with it)
> 
>  Documentation/trace/ftrace.rst | 7 ++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/Documentation/trace/ftrace.rst b/Documentation/trace/ftrace.rst
> index e45f0786f3f9..9bbd3aefadb2 100644
> --- a/Documentation/trace/ftrace.rst
> +++ b/Documentation/trace/ftrace.rst
> @@ -224,6 +224,8 @@ of ftrace. Here is a list of some of the key files:
>   has a side effect of enabling or disabling specific functions
>   to be traced. Echoing names of functions into this file
>   will limit the trace to only those functions.
> + This influences the tracers "function" and "function_graph"
> + and thus also function profiling (see "function_profile_enabled").
>  
>   The functions listed in "available_filter_functions" are what
>   can be written into this file.
> @@ -265,6 +267,8 @@ of ftrace. Here is a list of some of the key files:
>   Functions listed in this file will cause the function graph
>   tracer to only trace these functions and the functions that
>   they call. (See the section "dynamic ftrace" for more details).
> + Note, set_ftrace_filter and set_ftrace_notrace still affects
> + what functions are being traced.
>  
>set_graph_notrace:
>  
> @@ -277,7 +281,8 @@ of ftrace. Here is a list of some of the key files:
>  
>   This lists the functions that ftrace has processed and can trace.
>   These are the function names that you can pass to
> - "set_ftrace_filter" or "set_ftrace_notrace".
> + "set_ftrace_filter", "set_ftrace_notrace",
> + "set_graph_function", or "set_graph_notrace".
>   (See the section "dynamic ftrace" below for more details.)
>  
>dyn_ftrace_total_info:

--
To unsubscribe from this list: send the line "unsubscribe linux-doc" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html