Re: [PATCH v4 bpf-next 0/4] bpftool: introduce prog profile

[Quentin Monnet <quentin@isovalent.com>]

2020-03-04 10:07 UTC-0800 ~ Song Liu <songliubraving@fb.com>
> This set introduces bpftool prog profile command, which uses hardware
> counters to profile BPF programs.
> 
> This command attaches fentry/fexit programs to a target program. These two
> programs read hardware counters before and after the target program and
> calculate the difference.
> 
> Changes v3 => v4:
> 1. Simplify err handling in profile_open_perf_events() (Quentin);
> 2. Remove redundant p_err() (Quentin);
> 3. Replace tab with space in bash-completion; (Quentin);
> 4. Fix typo _bpftool_get_map_names => _bpftool_get_prog_names (Quentin).
> 
> Changes v2 => v3:
> 1. Change order of arguments (Quentin), as:
>      bpftool prog profile PROG [duration DURATION] METRICs
> 2. Add bash-completion for bpftool prog profile (Quentin);
> 3. Fix build of selftests (Yonghong);
> 4. Better handling of bpf_map_lookup_elem() returns (Yonghong);
> 5. Improve clean up logic of do_profile() (Yonghong);
> 6. Other smaller fixes/cleanups.
> 
> Changes RFC => v2:
> 1. Use new bpf_program__set_attach_target() API;
> 2. Update output format to be perf-stat like (Alexei);
> 3. Incorporate skeleton generation into Makefile;
> 4. Make DURATION optional and Allow Ctrl-C (Alexei);
> 5. Add calcated values "insn per cycle" and "LLC misses per million isns".
> 
> Song Liu (4):
>   bpftool: introduce "prog profile" command
>   bpftool: Documentation for bpftool prog profile
>   bpftool: bash completion for "bpftool prog profile"
>   bpftool: fix typo in bash-completion
> 
>  .../bpftool/Documentation/bpftool-prog.rst    |  19 +
>  tools/bpf/bpftool/Makefile                    |  18 +
>  tools/bpf/bpftool/bash-completion/bpftool     |  47 +-
>  tools/bpf/bpftool/prog.c                      | 425 +++++++++++++++++-
>  tools/bpf/bpftool/skeleton/profiler.bpf.c     | 171 +++++++
>  tools/bpf/bpftool/skeleton/profiler.h         |  47 ++
>  tools/scripts/Makefile.include                |   1 +
>  7 files changed, 725 insertions(+), 3 deletions(-)
>  create mode 100644 tools/bpf/bpftool/skeleton/profiler.bpf.c
>  create mode 100644 tools/bpf/bpftool/skeleton/profiler.h
> 
> --

Thanks again! This version looks good to me, although I've not tested
the patchset, so there's still the error met by Jiri to figure out. For
the rest of the series:

Reviewed-by: Quentin Monnet <quentin@isovalent.com>