wait_for_completion_io(9)

💖 wait_for_completion_io 💖

okay bestie, we're in the Kernel API Manual and today's main character is wait_for_completion_io — no cap, it's the "wait for a task to finish" call, and it's giving very patient bestie energy. 🫶

✨ NAME ✨

wait_for_completion_io - - waits for completion of a task. literally the "bestie, are you done yet?" kernel call. 💅

💅 SYNOPSIS 💅

void wait_for_completion_io (struct completion *x );

🎀 ARGUMENTS 🎀

• x — holds the state of this particular completion. it's the little state-holder for this exact completion, iykyk. 🎀

🦋 DESCRIPTION 🦋

so this one waits to be signaled for completion of a specific task. that's the whole assignment. ✨

it is NOT interruptible, and there is no timeout — not me emphasizing that, but bestie, fr fr, those are the rules. 😭

the caller is accounted as waiting for IO (which traditionally means blkio only). so yes, it's giving IO-wait main character energy, but specifically the traditional blkio-only kind. 💅

🌈 SEE ALSO 🌈

check the kernel file ./kernel/sched/completion.c and these iconic besties:

• complete(9)
• complete_all(9)
• wait_for_completion(9)
• wait_for_completion_timeout(9)
• wait_for_completion_io_timeout(9)
• wait_for_completion_interruptible(9)
• wait_for_completion_interruptible_timeout(9)
• wait_for_completion_killable(9)
• wait_for_completion_killable_timeout(9)
• try_wait_for_completion(9)
• completion_done(9)

that's the whole vibe check 💖 from the Kernel API Manual, source/version ./kernel/sched, dated October 2026 — wait_for_completion_io(9) signing off 🫶💅