bpf_wakeup_s..._read_unlock(9)

📦 version 7.3.1, in nixpkgs unstable

💅 bpf_wakeup_s..._read_unlock(9) — a Kernel API Manual moment

okay so this is section 9 of the Kernel API Manual, and bestie, we're talking about bpf_wakeup_s..._read_unlock — yes the name is a whole entire keyboard smash, we don't make the rules, we just document them 💖

✨ NAME ✨

bpf_wakeup_sources_read_unlock — releases the SRCU lock for wakeup sources. that's it. that's the job. she opens the door and lets everybody out 🚪🦋

🌸 SYNOPSIS 🌸

__bpf_kfunc void bpf_wakeup_sources_read_unlock (struct bpf_ws_lock *lock );

🎀 ARGUMENTS 🎀

  • lock — the opaque pointer you got back from bpf_wakeup_sources_read_lock. no cap, it's opaque, you're not supposed to peek inside it, just hand it back like a library book 🫶

👑 DESCRIPTION 👑

so here's the tea ☕: the BPF verifier has already done the vibe check for you — it guarantees that lock is a valid, unreleased pointer that came from the acquire function. so you literally cannot fumble this. she checked, she signed off, it's iconic.

then we do the actual bit: we decode the pointer back into the integer SRCU index by subtracting 1, and we release the lock. one (1) minus. that's the whole trick. ate and left no crumbs 🔥

ngl it looks like nothing, but this is the release half of an acquire/release pair — the matching unlock for bpf_wakeup_sources_read_lock. keep the pair together, periodt.

💫 SEE ALSO 💫

Kernel file: ./drivers/base/power/wakeup.c — and the whole friend group:

mwah, that's a wrap 🧚💜 this lil page lives over in ./drivers/base/power, dated October 2026 — go forth and unlock responsibly, bestie. bpf_wakeup_s..._read_unlock(9) out! 🌈

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