sugov_iowait_boost(9)

💅 sugov_iowait_boost(9) — like, the Kernel API Manual bestie ✨

okay so picture this: it's giving kernel scheduler, it's giving cpufreq, and this one little function is out here updating the IO boost status of a CPU. that's it, that's the vibe. 🦋

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✨ NAME ✨

sugov_iowait_boost — Updates the IO boost status of a CPU. no cap, that's literally the whole job. 🎀

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🌸 SYNOPSIS 🌸

void sugov_iowait_boost (struct sugov_cpu *sg_cpu , u64 time , unsigned
int flags );

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🫶 ARGUMENTS 🫶

• sg_cpu — the sugov data for the CPU to boost. like, the actual little data bundle for whichever CPU we're hyping up 💖
• time — the update time, handed to us by the caller. respectfully, we did not pick this timestamp, they did ⭐
• flags — SCHED_CPUFREQ_IOWAIT if the task is waking up after an IO wait. that's the flag that says "bestie just came back from IO" 👀

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🔥 DESCRIPTION 🔥

okay so here's the lore. every single time a task wakes up after an IO operation, the CPU utilization can be boosted to a certain utilization. and the way that certain utilization doubles at each "frequent and successive" wakeup from IO?? iconic behaviour honestly. ✨

and the range on this thing? it goes from IOWAIT_BOOST_MIN all the way up to the utilization of the maximum OPP. so it starts cute and small and can climb to the tippy top 👑

but here's the catch bestie, listen — to keep that doubling going, an IO boost has to be requested at least once per tick. miss a tick and it's over, we restart from the utilization of the minimum OPP. no doubling, no drama, just back to the bottom 😭 that's the rule, periodt.

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🌈 SEE ALSO 🌈

• Kernel file ./kernel/sched/cpufreq_schedutil.c — the source file, the main character itself 💅
• get_capacity_ref_freq(9)
• get_next_freq(9)
• sugov_iowait_reset(9)
• sugov_iowait_apply(9)

go read those too, they're all in the same friend group 🧚

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aaaand that's the page!! mwah 💜 this little drop of kernel wisdom came from ./kernel/sched, dated October 2026 — so yeah, take that timestamp and remember us by it 🍓🌸