percpu_ref_kill(9)

Bestie!! 💖 You're reading the Kernel API Manual, and today's main character is percpu_ref_kill(9) — the "drop the initial ref" girlie. Let's get into it. 🎀

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✨ NAME ✨

percpu_ref_kill — drop the initial ref 🫶

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🌸 SYNOPSIS 🌸

void percpu_ref_kill (struct percpu_ref *ref );

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🦋 ARGUMENTS 🦋

• ref — the percpu_ref you're about to kill 💀. That's it. That's the whole argument. Slay.

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💖 DESCRIPTION 💖

Okay so here's the tea, bestie. 🍵 You must use percpu_ref_kill to drop the initial ref on a percpu refcount. And the way that it has to be called is precisely once before shutdown. Not twice. Not zero times. Precisely once. Periodt. 👑

What it's doing under the hood: it switches ref into atomic mode first, then gathers up the percpu counters, and then drops the initial ref. So it's serving atomic-mode realness before it cleans up the counters. ✨

⚠️ Major vibe check: there are no implied RCU grace periods between kill and release. None. Zero. Nada. Don't be out here assuming one, because the kernel is not giving it to you. 💀

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👑 SEE ALSO 👑

Kernel file ./include/linux/percpu-refcount.h — go read it, bestie, it's right there 🫶:

• percpu_ref_get_many(9)
• percpu_ref_get(9)
• percpu_ref_tryget_many(9)
• percpu_ref_tryget(9)
• percpu_ref_tryget_live_rcu(9)
• percpu_ref_tryget_live(9)
• percpu_ref_put_many(9)
• percpu_ref_put(9)
• percpu_ref_is_dying(9)

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And that's the whole page, bestie!! 💖 This little masterpiece lives in ./include/linux, dated October 2026, and it's filed under percpu_ref_kill(9) — mwah, catch you on the next man page! 💋🎀