Re: [RFC PATCH bpf-next v2 3/5] sched_ext: Add scx_kfunc_ids_ops_context for unified filtering of context-sensitive SCX kfuncs

[Alexei Starovoitov]

On Fri, Feb 14, 2025 at 12:13 PM Juntong Deng <juntong.deng@xxxxxxxxxxx> wrote:
> +static int scx_kfunc_ids_ops_context_filter(const struct bpf_prog *prog, u32 kfunc_id)
> +{
> +       u32 moff, flags;
> +
> +       if (!btf_id_set8_contains(&scx_kfunc_ids_ops_context, kfunc_id))
> +               return 0;
> +
> +       if (prog->type == BPF_PROG_TYPE_SYSCALL &&
> +           btf_id_set8_contains(&scx_kfunc_ids_unlocked, kfunc_id))
> +               return 0;
> +
> +       if (prog->type == BPF_PROG_TYPE_STRUCT_OPS &&
> +           prog->aux->st_ops != &bpf_sched_ext_ops)
> +               return 0;
> +
> +       /* prog->type == BPF_PROG_TYPE_STRUCT_OPS && prog->aux->st_ops == &bpf_sched_ext_ops*/
> +
> +       moff = prog->aux->attach_st_ops_member_off;
> +       flags = scx_ops_context_flags[SCX_MOFF_IDX(moff)];
> +
> +       if ((flags & SCX_OPS_KF_UNLOCKED) &&
> +           btf_id_set8_contains(&scx_kfunc_ids_unlocked, kfunc_id))
> +               return 0;
> +
> +       if ((flags & SCX_OPS_KF_CPU_RELEASE) &&
> +           btf_id_set8_contains(&scx_kfunc_ids_cpu_release, kfunc_id))
> +               return 0;
> +
> +       if ((flags & SCX_OPS_KF_DISPATCH) &&
> +           btf_id_set8_contains(&scx_kfunc_ids_dispatch, kfunc_id))
> +               return 0;
> +
> +       if ((flags & SCX_OPS_KF_ENQUEUE) &&
> +           btf_id_set8_contains(&scx_kfunc_ids_enqueue_dispatch, kfunc_id))
> +               return 0;
> +
> +       if ((flags & SCX_OPS_KF_SELECT_CPU) &&
> +           btf_id_set8_contains(&scx_kfunc_ids_select_cpu, kfunc_id))
> +               return 0;
> +
> +       return -EACCES;
> +}

This looks great.
Very good cleanup and run-time speed up.
Please resend without RFC tag, so sched-ext folks can review.

>From bpf pov, pls add my Ack to patch 1 when you respin.
The set can probably target sched-ext tree too.