update_cpumask(9)

💖 NAME 💖

okay bestie, this is update_cpumask from the Kernel API Manual, and it does exactly what the name says: update the cpus_allowed mask of a cpuset and all tasks in it. that’s the whole vibe, no cap ✨

✨ SYNOPSIS ✨

here’s the exact signature, bestie — keep the spaces and the line break exactly as they are, do not “fix” them, i’m begging:

int update_cpumask (struct cpuset *cs , struct cpuset *trialcs , const
       char *buf );

🎀 ARGUMENTS 🎀

• cs — the cpuset to consider. like, the one we’re looking at 👀
• trialcs — trial cpuset. yes, a trial cpuset, very demure, very mindful 🎀
• buf — buffer of cpu numbers written to this cpuset. raw cpu numbers, no extra commentary 💅

🦋 SEE ALSO 🦋

first up, the kernel file is ./kernel/cgroup/cpuset.c — that’s the spot, bestie. and here’s the whole see-also friend group, all listed exactly as the original says:

• cpuset_lock(9)
• cpuset_full_lock(9)
• partition_is_populated(9)
• alloc_cpumasks(9)
• alloc_tmpmasks(9)
• free_tmpmasks(9)
• dup_or_alloc_cpuset(9)
• free_cpuset(9)
• cpus_excl_conflict(9)
• cpuset_update_tasks_cpumask(9)
• compute_effective_cpumask(9)
• compute_effective_nodemask(9)
• rm_siblings_excl_cpus(9)
• update_parent_effective_cpumask(9)
• compute_partition_effective_cpumask(9)
• update_sibling_cpumasks(9)
• validate_partition(9)
• partition_cpus_change(9)
• update_exclusive_cpumask(9)
• cpuset_update_tasks_nodemask(9)
• update_prstate(9)
• cpuset_css_alloc(9)
• cpuset_init(9)
• cpuset_hotplug_update_tasks(9)
• cpuset_handle_hotplug(9)
• cpuset_init_smp(9)
• cpuset_cpus_allowed_locked(9)
• cpuset_cpus_allowed(9)
• cpuset_cpus_allowed_fallback(9)
• cpuset_mems_allowed(9)
• cpuset_nodemask_valid_mems_allowed(9)
• cpuset_nodes_allowed(9)
• cpuset_spread_node(9)
• cpuset_mem_spread_node(9)
• cpuset_mems_allowed_intersects(9)
• cpuset_print_current_mems_allowed(9)

xoxo, your girlie in the ./kernel/cgroup corner of the Kernel API Manual, dated October 2026, signing off on update_cpumask(9) — mwah 💅💖