smp_cond_load_relaxed(9)

💅 smp_cond_load_relaxed(9) — Kernel API Manual 🎀

okay bestie, so this one's a kernel macro from the Kernel API Manual and it's called smp_cond_load_relaxed — yes that's a whole mouthful, we're gonna get through it together 🫶. And ngl, the name is doing exactly what it says on the tin: it (spin) waits for cond, and it gives you no ordering guarantees. Periodt.

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🌸 SYNOPSIS 🌸

smp_cond_load_relaxed (ptr , cond_expr );

like, two args, that's it, slay ✨

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✨ ARGUMENTS ✨

• ptr — pointer to the variable to wait on. this is your main character, the thing you're staring at 👀
• cond_expr — boolean expression to wait for. the vibe check you're waiting to pass 💖

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💀 DESCRIPTION 💀

So what does it actually do? It's equivalent to using READ_ONCE on the condition variable — that's the whole energy. no cap.

And here's the tea about why it works the way it does: due to C lacking lambda expressions, we can't just hand it a cute little inline function. so instead, it loads the value of *ptr into a pre-named variable VAL which is the thing you get to use in cond. that's it, that's the trick — VAL is literally just sitting there pre-named so your condition has something to refer to. iconic workaround, honestly 🧚

⚠️ heads up bestie: the "relaxed" in the name is not a vibe, it's a promise — no ordering guarantees. if you needed ordering, you're at the wrong function, iykyk. go look at the acquire one 👇

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👑 SEE ALSO 👑

• Kernel file: ./include/asm-generic/barrier.h — literally the source, go read it 💜
• smp_acquire__after_ctrl_dep(9) — the dependency-ordering bestie 🌈
• smp_cond_load_acquire(9) — same-ish energy, but with acquire ordering, so if you need guarantees, this is your girl ⭐

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🎀 and that's the whole page!! sourced from ./include/asm-generic, dated October 2026, and it's smp_cond_load_relaxed(9) all day babes — go wait on a condition, but relaxedly 💅💖🔥