cgroup_migrate_add_task(9)

💅 cgroup_migrate_add_task(9) ✨

okay bestie, welcome to the Kernel API Manual — yes this is a (9) page, we're in kernel-internals territory, and we're gonna get through it together 🫶

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🌸 NAME 🌸

cgroup_migrate_add_task — add a migration target task to a migration context 💖

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✨ SYNOPSIS ✨

void cgroup_migrate_add_task (struct task_struct *task , struct
       cgroup_mgctx *mgctx );

like, it returns void. nothing back. it just does the thing and leaves, main character energy fr fr 👑

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🎀 ARGUMENTS 🎀

• task — the target task, aka the little guy we're trying to move 🦋
• mgctx — the target migration context, aka the group chat this whole operation is happening in 💬

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🌈 DESCRIPTION 🌈

So here's the vibe: you take task — which is a migration target, important detail, don't forget it — and you add it to mgctx->tset. That's it, that's the job 💅

ngl the cute part is this function becomes a noop if task doesn't need to be migrated. Like, it just... doesn't do anything. honestly relatable 🙈

But before any of this works, two things gotta be true:

• task's css_set should have been added as a migration source — like, that's a prerequisite, no cap
• task->cg_list will be moved from the css_set's tasks list over to the mg_tasks one — the way that list just relocates itself, we love a glow-up ✨

okay so technically this is a void function and there's no return value to check — the "should have been" about the css_set is literally in the original, so treat it as a precondition bestie, not a suggestion 🫶

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🔥 SEE ALSO 🔥

the kernel file lives at ./kernel/cgroup/cgroup.c and honestly the whole friend group shows up here — say hi to everybody:

• 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_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)

like... that's the whole roster. everyone ate 💀🔥

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and that's the page bestie!! before you go — this one's sourced from ./kernel/cgroup, dated October 2026, and it's the cgroup_migrate_add_task(9) page itself. mwah, go migrate some tasks responsibly 💜🎀🧚