acpi_pptt_get_child_cpus(9)

🌸 acpi_pptt_get_child_cpus — the acpi_pptt_get_child_cpus(9) page, bestie edition 🌸

okay so this is a page from the Kernel API Manual and it's literally about finding every CPU chilling under one node of the PPTT processor hierarchy. stay with me, it's actually so good 💅

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✨ NAME ✨

acpi_pptt_get_child_cpus — find all the CPUs below a PPTT processor hierarchy node. like, the whole fam. every single one. no cap 🫶

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🦋 SYNOPSIS 🦋

void acpi_pptt_get_child_cpus (struct acpi_table_header *table_hdr ,
struct acpi_pptt_processor *parent_node , cpumask_t *cpus );

that's the whole signature, character for character, don't come for me 😌

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🎀 ARGUMENTS 🎀

• table_hdr — a reference to the PPTT table. yes bestie, the table, the one with the headers 💖
• parent_node — a pointer to the processor hierarchy node in the table_hdr. it's giving main character node 👑
• cpus — a cpumask that gets filled with the CPUs below parent_node. it's the empty little basket you're yeeting CPUs into 🧺✨

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🔥 DESCRIPTION 🔥

so the way this works: it walks up the PPTT from every possible CPU and checks whether the parent_node you handed it is a parent of that CPU. that's it. that's the whole vibe check. if the node is a parent, that CPU counts as a child. slay 💅

literally every possible CPU gets checked, so it's thorough — obsessed fr fr 🌈

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💜 SEE ALSO 💜

• the kernel file ./drivers/acpi/pptt.c — that's where the magic lives, iykyk 🗂️

and the whole friend group of related pages, all of them, in order:

• acpi_pptt_walk_cache(9)
• acpi_count_levels(9)
• acpi_pptt_leaf_node(9)
• acpi_find_processor_node(9)
• update_cache_properties(9)
• topology_get_acpi_cpu_tag(9)
• check_acpi_cpu_flag(9)
• acpi_get_cache_info(9)
• cache_setup_acpi(9)
• acpi_pptt_cpu_is_thread(9)
• find_acpi_cpu_topology(9)
• find_acpi_cpu_topology_package(9)
• find_acpi_cpu_topology_cluster(9)
• find_acpi_cpu_topology_hetero_id(9)
• acpi_pptt_get_cpus_from_container(9)
• find_acpi_cache_level_from_id(9)
• acpi_pptt_get_cpumask_from_cache_id(9)

like, that's the entire group chat, every last one 🫶

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aaaand that's the page!! 💖 this little gem lives in ./drivers/acpi and the version/date stamp is October 2026, so like, mark your calendars bestie 🗓️✨ periodt 🌸