[PATCH v11 0/8] function_graph: Support recording and printing the return value of function

[Steven Rostedt]

On Sat,  8 Apr 2023 05:42:14 -0700
Donglin Peng <pengdonglin at sangfor.com.cn> 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.
> 
> Note that even if a function's return type is void, a return value will
> still be printed, so it should be ignored. If you care about this, the
> BTF file can be used to obtain the details of function return type. We
> can implement a tool to process the trace log and display the return
> value based on its actual type.
> 
> Here is an example:
> 
> 

I like this series, but since the merge window for 6.4 just opened, I'm
going to hold off and pull this in for the 6.5 series (after a bit more
review and testing).

-- Steve