update_cache_properties(9)

💅 update_cache_properties(9) — from the Kernel API Manual, bestie

Okay so welcome to the Kernel API Manual, girlies ✨ — today's main character is update_cache_properties, and yes she's a real one in the ./drivers/acpi directory. Let's get into it 🎀

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✨ NAME ✨

update_cache_properties — updates the cacheinfo for the processor you're pointing at, no cap 🧚

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🌸 SYNOPSIS 🌸

void update_cache_properties (struct cacheinfo *this_leaf , struct
       acpi_pptt_cache *found_cache , struct acpi_pptt_processor *cpu_node );

Literally that's the whole signature, copy it exactly, don't be weird about the spacing 💖

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🦋 ARGUMENTS 🦋

• this_leaf — the kernel cache info structure that's getting updated rn. She's the one being edited, okay? 👑
• found_cache — the PPTT node that describes this particular cache instance. It's giving "source of truth" energy ✨
• cpu_node — a unique reference used to describe this cache instance. One of a kind, fr fr 🫶

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💜 DESCRIPTION 💜

So here's the vibe: the ACPI spec implies that the fields inside the cache structures get used to extend and correct the info that was probed straight from the hardware. Like, hardware says one thing, ACPI comes in and is like "actually, let me add to that and fix that up" 😭

But — and this is the important part, bestie — we only set the fields that we determine are VALID. That's literally the rule. Nothing else gets touched. Periodt 💅

Not me being dramatic, but VALID is in all caps in the original for a reason. Only the fields we've confirmed are valid get set. No guessing, no vibes-based field assignment 🙈

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⭐ RETURN ⭐

nothing. 🫠

Yeah, she returns void — the actual glow-up is a side effect of updating the global cacheinfo. Main character energy doesn't always need a return value, iykyk 💀

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🔥 SEE ALSO 🔥

Bestie, the friend group here is LARGE, get comfy 🌈 — all of these live in the kernel file ./drivers/acpi/pptt.c:

• acpi_pptt_walk_cache(9)
• acpi_count_levels(9)
• acpi_pptt_leaf_node(9)
• acpi_find_processor_node(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_child_cpus(9)
• acpi_pptt_get_cpus_from_container(9)
• find_acpi_cache_level_from_id(9)
• acpi_pptt_get_cpumask_from_cache_id(9)

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💖 that's the whole page, you ate that 💖

Cute little sign-off for the credits, because we always give credit 🎀: this one's sourced from ./drivers/acpi, dated October 2026, and the page itself is update_cache_properties(9) in the Kernel API Manual. Slay, bye 👋✨