r4k_op_needs_ipi(9)

💅 r4k_op_needs_ipi(9) — from the Kernel API Manual, bestie

Okay so picture this: you're in the MIPS kernel, you've got a cache op to do, and you need to know whether it's a whole-system situation or just a "one CPU is fine" moment. That's this function. It's the vibe check for cache operations. Let's get into it 🫶

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✨ NAME ✨

r4k_op_needs_ipi — literally decides if a cache op needs to be done on every core. Every single one. No skipping 💅

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🌸 SYNOPSIS 🌸

bool r4k_op_needs_ipi (unsigned int type );

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🎀 ARGUMENTS 🎀

• type — the type of cache operations. Your options are R4K_HIT or R4K_INDEX. That's it, that's the menu 🍓

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🦋 DESCRIPTION 🦋

So what it does: it decides whether a cache op needs to be performed on every core in the system. Every. Core. 🌈

And here's the tea — the answer isn't fixed! It may change depending on the type of cache operation, and also on the set of online CPUs. So because of that, preemption should be disabled by the caller to prevent CPU hotplug from changing the result. Important!! Don't skip that part, fr fr 😭

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🔥 RETURN 🔥

• Returns 1 if the cache operation type should be done on every core in the system 👑
• Returns 0 if the cache operation type is globalized and only needs to be performed on a simple CPU ✨

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🌈 SEE ALSO 🌈

• Kernel file ./arch/mips/mm/c-r4k.c
• has_valid_asid(9)

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ngl, the whole "preemption should be disabled" thing is not a suggestion — if the CPU set shifts under you mid-decision, that's a bad time 💀

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That's the page, bestie! It lives under ./arch/mips/mm in the Kernel API Manual, dated October 2026, and it goes by r4k_op_needs_ipi(9) — iconic, no cap 💖🎀