compute_effective_cpumask(9)

💅 compute_effective_cpumask(9) 💅

okay so bestie, we're in the Kernel API Manual and the main character is compute_effective_cpumask(9). it computes the effective cpumask of the cpuset. that's the vibe. ✨

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🌸 NAME 🌸

compute_effective_cpumask — compute the effective cpumask of the cpuset. love that for us 💖

✨ SYNOPSIS ✨

void compute_effective_cpumask (struct cpumask *new_cpus , struct cpuset
       *cs , struct cpuset *parent );

🎀 ARGUMENTS 🎀

• new_cpus — the temp variable for the new effective_cpus mask. it's giving scratch-space energy 🫶
• cs — the cpuset the need to recompute the new effective_cpus mask. yes bestie, this one is getting recomputed 💅
• parent — the parent cpuset. the mothership, if you will 👑

🦋 DESCRIPTION 🦋

so for v2, the parent's effective_cpus is inherited if the cpumask is empty. inheritance moment, honestly ✨

and the result is valid only if the given cpuset isn't a partition root.

🚨 caveat alert: the result is valid only if the given cpuset isn't a partition root. don't forget it, i'm begging 😭

🌈 SEE ALSO 🌈

Kernel file: ./kernel/cgroup/cpuset.c — it's right there, go look 🫶

then the whole icon crew, no skips:

• 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_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_cpumask(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)

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🎀 cute sign-off 🎀

that's the page, bestie! source is ./kernel/cgroup, the date is October 2026, and the page is compute_effective_cpumask(9). go slay your cpusets 💅✨