Re: [PATCH bpf-next 01/16] bpf: Introduce map flag BPF_F_DYNPTR_IN_KEY

[Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx>]

On Tue, Oct 8, 2024 at 2:02 AM Hou Tao <houtao@xxxxxxxxxxxxxxx> wrote:
>
> index c6cd7c7aeeee..07f7df308a01 100644
> --- a/include/uapi/linux/bpf.h
> +++ b/include/uapi/linux/bpf.h
> @@ -1409,6 +1409,9 @@ enum {
>
>  /* Do not translate kernel bpf_arena pointers to user pointers */
>         BPF_F_NO_USER_CONV      = (1U << 18),
> +
> +/* Create a map with bpf_dynptr in key */
> +       BPF_F_DYNPTR_IN_KEY     = (1U << 19),
>  };

If I'm reading the other patches correctly this uapi flag
is unnecessary.
BTF describes the fields and dynptr is either there or not.
Why require users to add an extra flag ?