wait_event_idle_timeout(9)

💤 wait_event_idle_timeout(9) — the kernel API manual, but make it cute

okay so bestie, we're in the Kernel API Manual and today's main character is wait_event_idle_timeout 🎀 like, this is a 9-section manpage, iykyk. Buckle up.

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✨ NAME ✨

wait_event_idle_timeout — sleep without load until a condition becomes true or a timeout elapses 😴⏰

Literally the whole vibe: you nap (but like, productively) until your thing happens or the clock runs out. No cap.

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🌸 SYNOPSIS 🌸

wait_event_idle_timeout (wq_head , condition , timeout );

Three args, that's it, slay. 💅

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🦋 ARGUMENTS 🦋

• wq_head — the waitqueue to wait on 💤 like, this is the line you're queued up in.
• condition — a C expression for the event to wait for ✨ the thing you're manifesting, fr fr.
• timeout — timeout, in jiffies ⏳ yes, jiffies, not seconds, don't come for me.

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💖 DESCRIPTION 💖

The process is put to sleep (TASK_IDLE) until the condition evaluates to true 🔥 note the TASK_IDLE — that's the "no load" part, so the scheduler isn't mad at you.

The condition is checked each time the waitqueue wq_head is woken up 👀 every single wakeup = a fresh vibe check on your condition.

⚠️ ok important bestie: wake_up has to be called after changing any variable that could change the result of the wait condition. Like, if you flip the variable and don't call wake_up, nobody knows. the sleeper just keeps sleeping. embarrassing. 💀

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👑 RETURN 👑

Here's the tea on what you get back:

• 0 if the condition evaluated to false after the timeout elapsed 🙈 (timeout hit, condition said no)
• 1 if the condition evaluated to true after the timeout elapsed 🤨 (timeout hit, but the condition did land true — iconic but late)
• the remaining jiffies (at least 1) if the condition evaluated to true before the timeout elapsed 🌈 (early win! you get the leftover jiffies back, minimum 1)

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🧚 SEE ALSO 🧚

All the siblings, and yes there are so many, family reunion energy 🫶

Kernel file ./include/linux/wait.h — waitqueue_active(9), wq_has_single_sleeper(9), wq_has_sleeper(9), wake_up_pollfree(9), wait_event(9), wait_event_freezable(9), wait_event_timeout(9), wait_event_cmd(9), wait_event_interruptible(9), wait_event_interruptible_timeout(9), wait_event_hrtimeout(9), wait_event_interruptible_hrtimeout(9), wait_event_idle(9), wait_event_idle_exclusive(9), wait_event_idle_exclusive_timeout(9), wait_event_interruptible_locked(9), wait_event_interruptible_locked_irq(9), wait_event_interruptible_exclusive_locked(9), wait_event_interruptible_exclusive_locked_irq(9), wait_event_killable(9), wait_event_state(9), wait_event_killable_timeout(9), wait_event_lock_irq_cmd(9), wait_event_lock_irq(9), wait_event_interruptible_lock_irq_cmd(9), wait_event_interruptible_lock_irq(9), wait_event_interruptible_lock_irq_timeout(9)

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💅 and that's the page 💅

shoutout to ./include/linux for housing this whole situation, this version is dated October 2026 ⭐ and the source/version line says ./include/linux + October 2026 + wait_event_idle_timeout(9) — so yeah, that's the sign-off, love u, bye 🍓✨