css_has_online_children(9)

🌸 NAME 🌸

okay bestie, welcome to css_has_online_children(9) from the Kernel API Manual ✨ This one is literally a vibe check for a css: does a css have online children? 💖

🦋 SYNOPSIS 🦋

bool css_has_online_children (struct cgroup_subsys_state *css );

🎀 ARGUMENTS 🎀

• css — the target css. like, the one you're checking, bestie 🫶

💅 DESCRIPTION 💅

okay so it returns true if css has any online children; otherwise, it returns false. 🦋

⚠️ it can be called from any context, but the caller is responsible for synchronizing against on/offlining as necessary. that part is not a drill, bestie — sync it yourself 💀

👑 SEE ALSO 👑

the whole cgroup crew from the kernel file ./kernel/cgroup/cgroup.c is linked here, and yes, we're naming every single one because the lore matters:

• Kernel file: ./kernel/cgroup/cgroup.c
• 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)
• 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_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)

💖 final sign-off: source/version ./kernel/cgroup, date October 2026 — that's the footer, bestie, and we ate 💅