hwspin_lock_timeout(9)

📦 version 7.3.1, in nixpkgs unstable

💅 hwspin_lock_timeout — from the Kernel API Manual, bestie

okay so real talk: this page lives in the Kernel API Manual and it's about locking an hwspinlock but with a timeout limit so you don't just sit there forever like a clown. let's get into it 🎀

✨ NAME ✨

hwspin_lock_timeout — lock an hwspinlock with timeout limit 🔒⏰

🌸 SYNOPSIS 🌸

int hwspin_lock_timeout (struct hwspinlock *hwlock , unsigned int to );

🦋 ARGUMENTS 🦋

  • hwlock — the hwspinlock to be locked. this is the thing you want, bestie 👑
  • to — timeout value in msecs. yes, milliseconds, keep that energy 💅

💖 DESCRIPTION 💖

so this function locks the underlying hwlock. that's the whole vibe. but here's the tea: if the hwlock is already taken, the function will busy loop waiting for it to be released — except it gives up when timeout msecs have elapsed. so it's not gonna wait on it forever like some people we know 🙈

upon a successful return from this function, preemption is disabled — so the caller must not sleep. like, at all. not even a little nap 😭 and you're advised to release the hwspinlock as soon as possible. this is required in order to minimize remote cores polling on the hardware interconnect. no cap, that part matters 🔥

it returns 0 when the hwlock was successfully taken, and an appropriate error code otherwise — most notably an -ETIMEDOUT if the hwlock is still busy after timeout msecs. and the icon behavior: the function will never sleep 💀✨

fr fr, do not sleep in there. preemption is off. it's giving "main character who cannot be interrupted."

👑 SEE ALSO 👑

kernel file ./include/linux/hwspinlock.h, plus the whole friend group:

that's the whole page, mwah 💋 this one's brought to you by ./include/linux and dated October 2026 — go off, kernel docs 🫶⭐

📦 where this page comes from