poll_timeout_us(9)

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

okay so picture this: you're in kernel land, you've got an operation, you've got a condition, and you're just gonna sit there polling like a patient little angel until the condition hits or the clock runs out. that's the whole vibe of poll_timeout_us. it's giving "are we there yet" but make it ✨systems programming✨.

---

✨ NAME ✨

poll_timeout_us — periodically poll and perform an operation until a condition is met or a timeout occurs 🎀

like, it keeps doing The Thing, over and over, until either the condition says "we're done babe" or the timeout says "time's up sweetie." no cap.

---

🌸 SYNOPSIS 🌸

poll_timeout_us (op , cond , sleep_us , timeout_us , sleep_before_op );

that's the whole signature, crown and all 👑 — copy it exactly, don't get cute with it.

---

🦋 ARGUMENTS 🦋

• op — Operation. the thing you want to keep doing. the main character of the loop 💅
• cond — Break condition. when this goes true, we're out, we're done, we're free 🕊️
• sleep_us — Maximum time to sleep between operations, in us. and 0 means tight-loops — like, no sleeping at all, just absolutely feral spinning 😭. please read the usleep_range function description for details and limitations, fr fr, don't skip it.
• timeout_us — Timeout in us. and 0 means never timeout — it'll wait, like, forever, bestie. iconic of it honestly.
• sleep_before_op — if it is true, sleep sleep_us before the operation. like stretching before the gym, but for polling 🧚

---

💜 DESCRIPTION 💜

okay so real talk: when available, you'll probably want to use one of the specialized macros defined below rather than this macro directly. that's not me being shady, that's just the manpage being honest 🙈 — this one's the general-purpose girlie, the specialized ones are the specialists.

---

🌈 RETURN 🌈

• 0 on success — slay, we got there 🎉
• -ETIMEDOUT upon a timeout — the clock said no ❌

⚠️ ok this part is IMPORTANT, listen up: it must not be called from atomic context if sleep_us or timeout_us are used. like, don't do it. that's a you-problem you do not want 💀. atomic context + sleeping = bad time, no notes.

---

⭐ SEE ALSO ⭐

• Kernel file ./include/linux/iopoll.h — go read it, iykyk 📖
• poll_timeout_us_atomic(9)
• read_poll_timeout(9)
• read_poll_timeout_atomic(9)
• readx_poll_timeout(9)
• readx_poll_timeout_atomic(9)

the whole friend group, honestly 🫶 all of them.

---

and that's the tea, bestie — this page lives at ./include/linux, dated October 2026, and it's filed under poll_timeout_us(9). go poll responsibly, mwah 💖✨