[0/2] trace-cmd ftrace: support function retval feature in function_graph

Message

Jianfeng Wang April 15, 2024, 3:49 p.m. UTC

The upstream Linux kernel has introduced a funcgraph retval
feature for the function_graph tracer. (Commit ID:
a1be9ccc57f07d54278be34eed6bd679bc941c97). This feature can be
useful for debugging kernel problems, such as root cause
analysis for syscall errors.

This patch series is to utilize this feature to support
printing each function's return value in 'trace-cmd report'.
The default is off. Add a ftrace internal option so that
users can turn this feature on if they'd like to request for
the retval information in the function_graph tracer.

Jianfeng Wang (2):
  trace-cmd ftrace: print function retval in function_graph
  trace-cmd: Add ftrace options with fgraph retval option

 lib/trace-cmd/trace-ftrace.c | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)