cleanup_cgroup_environment(9)

✨ cleanup_cgroup_environment — bestie edition ✨

okay so this is a page from the Kernel API Manual (cleanup_cgroup_environment(9)) and honestly? it's the little janitor function that could 💅

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🌸 NAME 🌸

cleanup_cgroup_environment — Cleanup Cgroup Testing Environment 🧹✨

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🎀 SYNOPSIS 🎀

void cleanup_cgroup_environment (void );

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🦋 ARGUMENTS 🦋

• void — no arguments, bestie. zero. none. she takes nothing and she does the work anyway, main character energy fr 👑

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💜 DESCRIPTION 💜

okay so picture this: this function is idempotent, which means you can call her again and again and she literally does not care — she'll just keep calmly doing her thing. her whole job is deleting all the temporary cgroups that got created during the test, and unmounting the cgroup testing work directory. the cleanup queen 👑✨

at call time, she moves the calling process to the root cgroup, and then she runs the deletion process. so it's move-then-delete, in that order, no skipping steps 🫶

she is idempotent, and should not fail — unless a process is lingering 👀 (yes, a lingering process is the one thing that can ruin her vibe).

on failure, she'll print an error to stderr, and try to continue. like, she's not gonna throw the whole day away over one error, ngl 😭 she keeps going, that's the resilience 💪

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🔥 SEE ALSO 🔥

• Kernel file ./tools/testing/selftests/bpf/cgroup_helpers.c
• enable_controllers(9)
• write_cgroup_file(9)
• write_cgroup_file_parent(9)
• setup_cgroup_environment(9)
• join_cgroup(9)
• join_root_cgroup(9)
• join_parent_cgroup(9)
• set_cgroup_xattr(9)
• __cleanup_cgroup_environment(9)
• get_root_cgroup(9)
• create_and_get_cgroup(9)
• get_cgroup_id_from_path(9)
• setup_classid_environment(9)
• set_classid(9)
• join_classid(9)
• cleanup_classid_environment(9)
• get_classid_cgroup_id(9)
• get_cgroup1_hierarchy_id(9)
• open_classid(9)

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and that's the whole page, bestie 🍓 — sourced from ./tools/testing/selftests/bpf, dated October 2026, and honestly it ate 💅🏼✨