[PATCH v5 1/2] function_graph: Support recording and printing the return value of function

[Florian Kauer]

On 20.03.23 14:16, Donglin Peng wrote:
> When using the function_graph tracer to analyze system call failures,
> it can be time-consuming to analyze the trace logs and locate the kernel
> function that first returns an error. This change aims to simplify the
> process by recording the function return value to the 'retval' member of
> 'ftrace_graph_ent' and printing it when outputing the trace log.

I just came across your patch by pure luck and it helped me a lot
to trace down a problem I had, thanks!

So you can have my
Tested-by: Florian Kauer <florian.kauer at linutronix.de>
 
> New trace options are introduced: funcgraph-retval and graph_retval_hex.

I would personally prefer to have the second option scoped better, so for example
"funcgraph-retval-hex".

Greetings,
Florian