freq_qos_apply(9)

💅 freq_qos_apply(9) — the Kernel API Manual, bestie edition 🎀

okay so this is freq_qos_apply(9) from the Kernel API Manual, and it's literally the little helper that handles your frequency QoS requests — adding them, tweaking them, yeeting them. let's get into it ✨

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🌸 NAME 🌸

freq_qos_apply — add/modify/remove frequency QoS request. that's the whole vibe. she does three things and she does them well 💅

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🦋 SYNOPSIS 🦋

int freq_qos_apply(struct freq_qos_request *req, enum pm_qos_req_action action, s32 value);

it returns an int, she takes three things, and yes the parameter list is a little long — main character energy, she's allowed 🫶

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⭐ ARGUMENTS ⭐

• req — the constraint request you're applying. this is the request, the one getting the glow-up (or the goodbye) 💖
• action — the action to perform. your options are add / update / remove, so basically it's giving "make it exist, change it up, or take it out back" 😭
• value — the value to assign to the QoS request. the actual number going in 🍓

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🔥 DESCRIPTION 🔥

okay so listen. this one is only meant to be called from inside pm_qos — not from drivers. like. drivers, do not. i am begging 🙈 that's the entire warning, it's short but she means it.

bestie if you're writing a driver and you're about to call this — no you're not 💀 that's not your lane.

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👑 SEE ALSO 👑

the whole friend group, plus the file they all live in: ./kernel/power/qos.c 🧚

• pm_qos_read_value(9)
• pm_qos_update_target(9)
• pm_qos_flags_remove_req(9)
• pm_qos_update_flags(9)
• cpu_latency_qos_limit(9)
• cpu_latency_qos_request_active(9)
• cpu_latency_qos_add_request(9)
• cpu_latency_qos_update_request(9)
• cpu_latency_qos_remove_request(9)
• cpu_wakeup_latency_qos_limit(9)
• freq_constraints_init(9)
• freq_qos_read_value(9)
• freq_qos_add_request(9)
• freq_qos_update_request(9)
• freq_qos_remove_request(9)
• freq_qos_add_notifier(9)
• freq_qos_remove_notifier(9)

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and that's the page!! this icon comes to you courtesy of ./kernel/power, dated October 2026 — mwah, love u, read ur QoS docs 💜🌈⭐