Re: [PATCH v2 bpf-next 3/4] selftests/bpf: Add profiler test

[Song Liu <songliubraving@xxxxxx>]

> On Oct 13, 2020, at 2:56 PM, Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> wrote:

[...]

> 
> I'd go with Kconfig + bpf_core_enum_value(), as it's shorter and
> nicer. This compiles and works with my Kconfig, but I haven't checked
> with CONFIG_CGROUP_PIDS defined.

Tested with CONFIG_CGROUP_PIDS, it looks good. 

Tested-by: Song Liu <songliubraving@xxxxxx>

> 
> 
> diff --git a/tools/testing/selftests/bpf/progs/profiler.inc.h
> b/tools/testing/selftests/bpf/progs/profiler.inc.h
> index 00578311a423..79b8d2860a5c 100644
> --- a/tools/testing/selftests/bpf/progs/profiler.inc.h
> +++ b/tools/testing/selftests/bpf/progs/profiler.inc.h
> @@ -243,7 +243,11 @@ static ino_t get_inode_from_kernfs(struct
> kernfs_node* node)
>        }
> }
> 
> -int pids_cgrp_id = 1;
> +extern bool CONFIG_CGROUP_PIDS __kconfig __weak;
> +
> +enum cgroup_subsys_id___local {
> +       pids_cgrp_id___local = 1, /* anything but zero */
> +};
> 
> static INLINE void* populate_cgroup_info(struct cgroup_data_t* cgroup_data,
>                                         struct task_struct* task,
> @@ -253,7 +257,9 @@ static INLINE void* populate_cgroup_info(struct
> cgroup_data_t* cgroup_data,
>                BPF_CORE_READ(task, nsproxy, cgroup_ns, root_cset,
> dfl_cgrp, kn);
>        struct kernfs_node* proc_kernfs = BPF_CORE_READ(task, cgroups,
> dfl_cgrp, kn);
> 
> -       if (ENABLE_CGROUP_V1_RESOLVER) {
> +       if (ENABLE_CGROUP_V1_RESOLVER && CONFIG_CGROUP_PIDS) {
> +               int cgrp_id = bpf_core_enum_value(enum
> cgroup_subsys_id___local, pids_cgrp_id___local);
> +
> #ifdef UNROLL
> #pragma unroll
> #endif
> @@ -262,7 +268,7 @@ static INLINE void* populate_cgroup_info(struct
> cgroup_data_t* cgroup_data,
>                                BPF_CORE_READ(task, cgroups, subsys[i]);
>                        if (subsys != NULL) {
>                                int subsys_id = BPF_CORE_READ(subsys, ss, id);
> -                               if (subsys_id == pids_cgrp_id) {
> +                               if (subsys_id == cgrp_id) {
>                                        proc_kernfs =
> BPF_CORE_READ(subsys, cgroup, kn);
>                                        root_kernfs =
> BPF_CORE_READ(subsys, ss, root, kf_root, kn);
>                                        break;