cgroup_css_set_put_fork(9)

💅 NAME 💅

cgroup_css_set_put_fork — the cleanup bestie that drops the references we grabbed during fork, no cap ✨

okay so real talk, this is a page straight out of the Kernel API Manual (Kernel API Manual), and it's all about cgroup_css_set_put_fork(9) — the little function that undoes what the fork path set up. she's giving cleanup era and honestly? iconic 🎀

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✨ SYNOPSIS ✨

void cgroup_css_set_put_fork (struct kernel_clone_args *kargs );

literally that's it. one function, one argument, void return because she does not owe you a report 💅

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🌸 ARGUMENTS 🌸

• kargs — the arguments that got passed in to create the child process, aka the receipts from the fork 🧾

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🦋 DESCRIPTION 🦋

okay so here's the vibe: this function drops references to the prepared css_set and the target cgroup — but only if CLONE_INTO_CGROUP was requested 🙈

that's the whole thing. if that flag wasn't in play, there's nothing to drop, so she just… doesn't. the way that she's conditional about it? lowkey respectful 💜

no cap, this is the "put the references back where you found them" moment. the fork path took them, and bestie here is the one who returns them. balance restored 🧚

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👑 SEE ALSO 👑

kernel file ./kernel/cgroup/cgroup.c, plus literally the entire cgroup cinematic universe 🌈 — grab a snack, this list is long and every single one of them is family:

cgroup_ssid_enabled(9), cgroup_on_dfl(9), cgroup_e_css_by_mask(9), cgroup_e_css(9), cgroup_get_e_css(9), __cgroup_task_count(9), cgroup_task_count(9), for_each_css(9), do_each_subsys_mask(9), css_set_populated(9), css_update_populated(9), css_set_update_populated(9), css_set_move_task(9), compare_css_sets(9), find_existing_css_set(9), allocate_cgrp_cset_links(9), link_css_set(9), find_css_set(9), cgroup_file_mode(9), cgroup_calc_subtree_ss_mask(9), cgroup_kn_unlock(9), cgroup_kn_lock_live(9), css_clear_dir(9), css_populate_dir(9), cgroup_attach_lock(9), cgroup_attach_unlock(9), cgroup_migrate_add_task(9), cgroup_taskset_first(9), cgroup_taskset_next(9), cgroup_migrate_execute(9), cgroup_migrate_vet_dst(9), cgroup_migrate_finish(9), cgroup_migrate_add_src(9), cgroup_migrate_prepare_dst(9), cgroup_migrate(9)

and continuing because she did not come to play 🫶:

cgroup_attach_task(9), cgroup_update_dfl_csses(9), cgroup_lock_and_drain_offline(9), cgroup_save_control(9), cgroup_propagate_control(9), cgroup_restore_control(9), cgroup_apply_control_enable(9), cgroup_apply_control_disable(9), cgroup_apply_control(9), cgroup_finalize_control(9), cgroup_enable_threaded(9), cgroup_tryget_css(9), cgroup_addrm_files(9), cgroup_rm_cftypes(9), cgroup_add_cftypes(9), cgroup_add_dfl_cftypes(9), cgroup_add_legacy_cftypes(9), cgroup_file_notify(9), cgroup_file_show(9), css_next_child(9), css_next_descendant_pre(9), css_rightmost_descendant(9), css_next_descendant_post(9), css_has_online_children(9), css_task_iter_advance_css_set(9), css_task_iter_start(9), css_task_iter_next(9), css_task_iter_end(9), css_create(9), kill_css_sync(9), kill_css_finish(9), cgroup_destroy_locked(9), cgroup_init_early(9), cgroup_init(9), cgroup_fork(9), cgroup_v1v2_get_from_file(9), cgroup_get_from_file(9), cgroup_css_set_fork(9), cgroup_can_fork(9), cgroup_cancel_fork(9), cgroup_post_fork(9), cgroup_task_exit(9), css_tryget_online_from_dir(9), css_from_id(9), cgroup_get_from_path(9), cgroup_v1v2_get_from_fd(9), cgroup_get_from_fd(9), cgroup_parse_float(9)

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and that's the whole page, bestie — no crumbs left behind 💅✨

sign-off time 🎀 this one lives in ./kernel/cgroup and it's dated October 2026, so like… future icon behaviour fr fr. bye pookie, go drop those references responsibly 🫶💖