Re: [PATCH bpf-next] bpftool: Print verified instruction count in prog show

[Quentin Monnet]

2026-10-16 15:16 UTC+0800 ~ chenyuan_fl@xxxxxxx
> From: Yuan Chen <chenyuan@xxxxxxxxxx>
> 
> The number of instructions processed by the verifier is available
> through bpf_prog_info::verified_insns and the program's fdinfo since
> commit aba64c7da983 ("bpf: Add verified_insns to bpf_prog_info and
> fdinfo"), but bpftool does not display it, leaving no convenient way
> to check a program's verifier cost.
> 
> Print the count in the plain and JSON output of bpftool prog show,
> following the convention of the other conditional stats
> (run_time_ns, run_cnt, recursion_misses): kernels that do not fill
> the field leave it zeroed and nothing is printed.


It's different from the other conditional stats though, unless you run
bpftool on an old kernel verified_insns will show up every time. Can we
move it to another line to avoid growing the first line too much,
please? Maybe after loaded_at and uid?


> 
> Signed-off-by: Yuan Chen <chenyuan@xxxxxxxxxx>
> ---
>  tools/bpf/bpftool/Documentation/bpftool-prog.rst | 3 ++-
>  tools/bpf/bpftool/prog.c                         | 4 ++++
>  2 files changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/bpf/bpftool/Documentation/bpftool-prog.rst b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
> index 8dbd34ef3d8b..d4a94e0737a9 100644
> --- a/tools/bpf/bpftool/Documentation/bpftool-prog.rst
> +++ b/tools/bpf/bpftool/Documentation/bpftool-prog.rst
> @@ -285,7 +285,7 @@ EXAMPLES
>  
>  ::
>  
> -    10: xdp  name some_prog  tag 005a3d2123620c8b  gpl run_time_ns 81632 run_cnt 10
> +    10: xdp  name some_prog  tag 005a3d2123620c8b  gpl run_time_ns 81632 run_cnt 10 verified_insns 528
>              loaded_at 2017-09-29T20:11:00+0000  uid 0
>              xlated 528B  jited 370B  memlock 4096B  map_ids 10
>              pids systemd(1)
> @@ -301,6 +301,7 @@ EXAMPLES
>              "gpl_compatible": true,
>              "run_time_ns": 81632,
>              "run_cnt": 10,
> +            "verified_insns": 528,
>              "loaded_at": 1506715860,
>              "uid": 0,
>              "bytes_xlated": 528,
> diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
> index eb077236d2ea..c77e871b8859 100644
> --- a/tools/bpf/bpftool/prog.c
> +++ b/tools/bpf/bpftool/prog.c
> @@ -441,6 +441,8 @@ static void print_prog_header_json(struct bpf_prog_info *info, int fd)
>  	}
>  	if (info->recursion_misses)
>  		jsonw_uint_field(json_wtr, "recursion_misses", info->recursion_misses);
> +	if (info->verified_insns)
> +		jsonw_uint_field(json_wtr, "verified_insns", info->verified_insns);
>  }
>  
>  static void print_prog_json(struct bpf_prog_info *info, int fd, bool orphaned)
> @@ -526,6 +528,8 @@ static void print_prog_header_plain(struct bpf_prog_info *info, int fd)
>  		       info->run_time_ns, info->run_cnt);
>  	if (info->recursion_misses)
>  		printf(" recursion_misses %llu", info->recursion_misses);
> +	if (info->verified_insns)
> +		printf(" verified_insns %u", info->verified_insns);


Note: Moving it to another line means you should use a double space
(rather than single) at the beginning of the string.

pw-bot: cr

Thanks,
Quentin