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From:   Hao Luo <haoluo@google.com>
Date:   Thu, 25 Aug 2022 13:35:01 -0700
Message-ID: <CA+khW7hHA2gjv_UhbyhU8HkFwemt4pARVw+e1SHHOteO60PF1g@mail.gmail.com>
Subject: Re: [PATCH bpf-next v9 1/5] bpf: Introduce cgroup iter
To:     Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc:     linux-kernel@vger.kernel.org, bpf@vger.kernel.org,
        cgroups@vger.kernel.org, netdev@vger.kernel.org,
        Alexei Starovoitov <ast@kernel.org>,
        Andrii Nakryiko <andrii@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Martin KaFai Lau <martin.lau@linux.dev>,
        Song Liu <song@kernel.org>, Yonghong Song <yhs@fb.com>,
        Tejun Heo <tj@kernel.org>, Zefan Li <lizefan.x@bytedance.com>,
        KP Singh <kpsingh@kernel.org>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Michal Hocko <mhocko@kernel.org>,
        John Fastabend <john.fastabend@gmail.com>,
        Jiri Olsa <jolsa@kernel.org>, Michal Koutny <mkoutny@suse.com>,
        Roman Gushchin <roman.gushchin@linux.dev>,
        David Rientjes <rientjes@google.com>,
        Stanislav Fomichev <sdf@google.com>,
        Shakeel Butt <shakeelb@google.com>,
        Yosry Ahmed <yosryahmed@google.com>
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On Thu, Aug 25, 2022 at 1:18 PM Andrii Nakryiko
<andrii.nakryiko@gmail.com> wrote:
>
> On Tue, Aug 23, 2022 at 8:01 PM Hao Luo <haoluo@google.com> wrote:
> >
[...]
> >  typedef int (*bpf_iter_attach_target_t)(struct bpf_prog *prog,
> > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> > index 934a2a8beb87..1c4e1c583880 100644
> > --- a/include/uapi/linux/bpf.h
> > +++ b/include/uapi/linux/bpf.h
> > @@ -87,10 +87,29 @@ struct bpf_cgroup_storage_key {
> >         __u32   attach_type;            /* program attach type (enum bpf_attach_type) */
> >  };
> >
> > +enum bpf_cgroup_iter_order {
> > +       BPF_ITER_ORDER_UNSPEC = 0,
> > +       BPF_ITER_SELF_ONLY,             /* process only a single object. */
> > +       BPF_ITER_DESCENDANTS_PRE,       /* walk descendants in pre-order. */
> > +       BPF_ITER_DESCENDANTS_POST,      /* walk descendants in post-order. */
> > +       BPF_ITER_ANCESTORS_UP,          /* walk ancestors upward. */
> > +};
>
> just skimming through this, I noticed that we have "enum
> bpf_cgroup_iter_order" (good, I like) but BPF_ITER_xxx with no CGROUP
> part in it (not good, don't like :). All the enumerator names have
> global visibility, so it would probably be best for them to be
> CGROUP-specific and roughly match the enum name itself:
> BPF_CGROUP_ITER_SELF_ONLY, etc?
>

Ack. I will send a patch to fix this right now.