sugov_iowait_apply(9)

✨ sugov_iowait_apply(9) ✨

okay bestie, welcome to the Kernel API Manual entry for sugov_iowait_apply(9) — yes that's the whole manual name, we're in the kernel API girlies now 💅

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🌸 NAME 🌸

sugov_iowait_apply — the girl who literally applies the IO boost to a CPU 🫶

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🦋 SYNOPSIS 🦋

unsigned long sugov_iowait_apply (struct sugov_cpu *sg_cpu , u64 time ,
       unsigned long max_cap );

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🎀 ARGUMENTS 🎀

• sg_cpu — the sugov data for the cpu to boost, i.e. the main character's data sheet 💖
• time — the update time from the caller, so like, when is this happening ⏰
• max_cap — the max CPU capacity, the ceiling, the limit, the max_cap 🧚

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🔥 DESCRIPTION 🔥

so here's the vibe ✨ A CPU running a task which woken up after an IO operation can have its utilization boosted to speed up the completion of those IO operations. like, it woke up from IO so we're giving it a little glow-up so it finishes faster, periodt.

The IO boost value is increased each time a task wakes up from IO, in sugov_iowait_boost, and it's instead decreased by this function, each time an increase has not been requested (!iowait_boost_pending). so: boost goes up over there, boost comes down over here when nobody's asking for more. balanced. iconic. 😌

A CPU which also appears to have been idle for at least one tick has also its IO boost utilization reset. ngl if you've been sitting idle for a tick or more, we're resetting that boost, no cap 🙈

This mechanism is designed to boost high frequently IO waiting tasks, while being more conservative on tasks which does sporadic IO operations. like it's literally built to hype up the constant-IO girlies and be lowkey chill with the ones who only show up every once in a while 🌈

fr fr, the whole point is heavy IO waiters get the boost and sporadic ones get treated more conservatively — that's the design, not a bug 💀

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👑 SEE ALSO 👑

• Kernel file ./kernel/sched/cpufreq_schedutil.c — and the whole squad: get_capacity_ref_freq(9), get_next_freq(9), sugov_iowait_reset(9), sugov_iowait_boost(9) 💜

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and that's a wrap bestie 🎀 this little drop came to you from ./kernel/sched, dated October 2026 — go forth and apply those boosts, sugov_iowait_apply(9) out 💅✨