compare_css_sets(9)

✨ compare_css_sets(9) ✨

okay so bestie, we're in the Kernel API Manual today and the star of the show is compare_css_sets(9) — she's a helper function, she's lowkey iconic, and honestly she does exactly one job and does it slayfully 💅

---

🌸 NAME 🌸

compare_css_sets — helper function for find_existing_css_set().

---

🦋 SYNOPSIS 🦋

bool compare_css_sets (struct css_set *cset , struct css_set *old_cset ,
struct cgroup *new_cgrp , struct cgroup_subsys_state *template[] );

---

🎀 ARGUMENTS 🎀

• cset — the candidate css_set that's getting tested rn, like she's auditioning for the role 🎤
• old_cset — the existing css_set for a task
• new_cgrp — the cgroup that's being entered by the task, aka the new location bestie is moving into 🏠
• template — the desired set of css pointers in the css_set, and yes it's pre-calculated so don't come for her about it ✨

---

💖 DESCRIPTION 💖

Returns true if cset matches old_cset except for the hierarchy which new_cgrp belongs to — for that one, it should match new_cgrp. So like, everything's the same... except the one thing that isn't 😭 periodt.

---

🔥 SEE ALSO 🔥

Kernel file ./kernel/cgroup/cgroup.c and honestly the whole friend group pull up here, no cap:

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), 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), 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_css_set_put_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)

---

👑 sign-off 👑

that's the whole page bestie, sourced from ./kernel/cgroup, dated October 2026 — go forth and compare those css sets, you're gonna eat 💖✨🫶