Re: [PATCH 6/6] ARM: ftrace: enable function graph tracer

[Catalin Marinas]

On Saturday, November 6, 2010, Rabin Vincent <rabin@xxxxxx> wrote:
> Add the options to enable the function graph tracer on ARM.  Function
> graph tracer support requires frame pointers, so exclude Thumb-2 and
> also explicitly select FRAME_POINTER in FUNCTION_GRAPH_TRACER since
> FUNCTION_TRACER doesn't select FRAME_POINTER when ARM_UNWIND is used
> Therefore, with GCC 4.4.0+, you get plain function tracing without frame
> pointers, but you'll need them if you want function graph tracing.
.....
> --- a/kernel/trace/Kconfig
> +++ b/kernel/trace/Kconfig
> @@ -141,6 +141,7 @@ config FUNCTION_TRACER
>
>  config FUNCTION_GRAPH_TRACER
>         bool "Kernel Function Graph Tracer"
> +       select FRAME_POINTER if ARM_UNWIND

Would it be better to modify FRAME_POINTER definition in the ARM
Kconfig so that it is enabled automatically when FUNCTION_GRAPH_TRACER
is enabled?

-- 
Catalin
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