diff options
| author | Matt Bobrowski <mattbobrowski@google.com> | 2026-01-27 08:51:10 +0000 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-01-27 09:05:54 -0800 |
| commit | 752b807028e63f1473b84eb1350e131eca5e5249 (patch) | |
| tree | 14099808ccce2765fb5e94314e4f8d764bfbceb9 /include | |
| parent | 8016abd6314ed1ed01ff09404e3c82ceb13c185b (diff) | |
bpf: add new BPF_CGROUP_ITER_CHILDREN control option
Currently, the BPF cgroup iterator supports walking descendants in
either pre-order (BPF_CGROUP_ITER_DESCENDANTS_PRE) or post-order
(BPF_CGROUP_ITER_DESCENDANTS_POST). These modes perform an exhaustive
depth-first search (DFS) of the hierarchy. In scenarios where a BPF
program may need to inspect only the direct children of a given parent
cgroup, a full DFS is unnecessarily expensive.
This patch introduces a new BPF cgroup iterator control option,
BPF_CGROUP_ITER_CHILDREN. This control option restricts the traversal
to the immediate children of a specified parent cgroup, allowing for
more targeted and efficient iteration, particularly when exhaustive
depth-first search (DFS) traversal is not required.
Signed-off-by: Matt Bobrowski <mattbobrowski@google.com>
Link: https://lore.kernel.org/r/20260127085112.3608687-1-mattbobrowski@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/uapi/linux/bpf.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 44e7dbc278e3..c8d400b7680a 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -119,6 +119,14 @@ enum bpf_cgroup_iter_order { BPF_CGROUP_ITER_DESCENDANTS_PRE, /* walk descendants in pre-order. */ BPF_CGROUP_ITER_DESCENDANTS_POST, /* walk descendants in post-order. */ BPF_CGROUP_ITER_ANCESTORS_UP, /* walk ancestors upward. */ + /* + * Walks the immediate children of the specified parent + * cgroup_subsys_state. Unlike BPF_CGROUP_ITER_DESCENDANTS_PRE, + * BPF_CGROUP_ITER_DESCENDANTS_POST, and BPF_CGROUP_ITER_ANCESTORS_UP + * the iterator does not include the specified parent as one of the + * returned iterator elements. + */ + BPF_CGROUP_ITER_CHILDREN, }; union bpf_iter_link_info { |