Re: [PATCH v5 0/8] perf trace: Augment enum arguments with BTF

[Ian Rogers]

On Fri, Jul 5, 2024 at 6:20 AM Howard Chu <howardchu95@xxxxxxxxx> wrote:
>
> Changes in v5:
>
> - Use hardcoded landlock structs and macros for landlock.c workload to
> make this build in older systems.

A few nits but otherwise:
Reviewed-by: Ian Rogers <irogers@xxxxxxxxxx>

Thanks,
Ian

> Changes in v4:
>
> - Fix landlock workload's build error.
>
> Changes in v3:
>
> - Add trace__btf_scnprintf() helper function
> - Remove is_enum memeber in struct syscall_arg_fmt, replace it with
> btf_is_enum()
> - Add syscall_arg_fmt__cache_btf_enum() to cache btf_type only
> - Resolve NO_LIBBPF=1 build error
> - Skip BTF augmentation test if landlock_add_rule syscall and LIBBPF are not
> available
> - Rename landlock.c workload, add a comment to landlock.c workload
> - Change the way of skipping 'enum ' prefix
> - Add type_name member to struct syscall_arg
>
> Changes in v2:
>
> - Add trace_btf_enum regression test, and landlock workload
>
> v1:
>
> In this patch, BTF is used to turn enum value to the corresponding
> enum variable name. There is only one system call that uses enum value
> as its argument, that is `landlock_add_rule()`.
>
> Enum arguments of non-syscall tracepoints can also be augmented, for
> instance timer:hrtimer_start and timer:hrtimer_init's 'mode' argument.
>
>
> Arnaldo Carvalho de Melo (2):
>   perf trace: Introduce trace__btf_scnprintf()
>   perf trace: Remove arg_fmt->is_enum, we can get that from the BTF type
>
> Howard Chu (6):
>   perf trace: Fix iteration of syscall ids in syscalltbl->entries
>   perf trace: BTF-based enum pretty printing for syscall args
>   perf trace: Augment non-syscall tracepoints with enum arguments with
>     BTF
>   perf trace: Filter enum arguments with enum names
>   perf test: Add landlock workload
>   perf test trace_btf_enum: Add regression test for the BTF augmentation
>     of enums in 'perf trace'
>
>  tools/perf/builtin-trace.c               | 229 ++++++++++++++++++++---
>  tools/perf/tests/builtin-test.c          |   1 +
>  tools/perf/tests/shell/trace_btf_enum.sh |  61 ++++++
>  tools/perf/tests/tests.h                 |   1 +
>  tools/perf/tests/workloads/Build         |   2 +
>  tools/perf/tests/workloads/landlock.c    |  66 +++++++
>  tools/perf/trace/beauty/beauty.h         |   1 +
>  tools/perf/util/syscalltbl.c             |   7 +
>  tools/perf/util/syscalltbl.h             |   1 +
>  9 files changed, 345 insertions(+), 24 deletions(-)
>  create mode 100755 tools/perf/tests/shell/trace_btf_enum.sh
>  create mode 100644 tools/perf/tests/workloads/landlock.c
>
> --
> 2.45.2
>