partition_cpus_change(9)

💅 partition_cpus_change — a Kernel API Manual moment ✨

okay so bestie, welcome to partition_cpus_change(9), a real one from the Kernel API Manual. this is the lil function that handles partition state changes when the CPU mask gets updated. she's giving quiet-but-essential energy, and honestly? iconic.

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🌸 NAME 🌸

partition_cpus_change — the one who handles partition state changes due to CPU mask updates 🎀

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✨ SYNOPSIS ✨

void partition_cpus_change (struct cpuset *cs , struct cpuset *trialcs ,
       struct tmpmasks *tmp );

like, look at her. three args, no notes. periodt.

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🦋 ARGUMENTS 🦋

• cs — the target cpuset being modified. this is the main character, the one getting changed up 💅
• trialcs — the trial cpuset containing the proposed configuration changes. think of her as the "what if" version, the draft, the vibe check 👀
• tmp — temporary masks for intermediate calculations. lowkey the messy middle steps, but we respect her 🫶

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💖 DESCRIPTION 💖

so basically, this function handles partition state transitions that get triggered by CPU mask changes. ngl, CPU modifications may cause a partition to be disabled, or they might require state updates — and partition_cpus_change is the one who shows up and deals with it. she's not doing the whole thing, she's just handling the partition-state-change part, and that's her lane. main character energy, but confined to her own plotline ✨

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🔥 SEE ALSO 🔥

• Kernel file ./kernel/cgroup/cpuset.c
• 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)
• 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)

that's the whole friend group right there. iykyk 💜

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🌈 sign-off 🌈

she lives in ./kernel/cgroup, dated October 2026, and this page is partition_cpus_change(9) — bestie, that's a wrap. slay, read the source, and stay hydrated 🍓🧚💖