mmu_interval_check_retry(9)

💅 mmu_interval_check_retry(9) — Kernel API Manual, but make it make sense

okay so bestie, welcome to mmu_interval_check_retry(9) from the Kernel API Manual — yes it's giving extremely niche kernel-core, but trust me, it's lowkey iconic once you get it. this is the lil vibe-check function that tells u whether a collision has happened. let's go 🎀

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✨ NAME ✨

mmu_interval_check_retry — literally just tests if a collision has occurred. that's the whole job. no cap. 💅

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🦋 SYNOPSIS 🦋

bool mmu_interval_check_retry (struct mmu_interval_notifier
*interval_sub , unsigned long seq );

she returns a bool, she takes a struct mmu_interval_notifier *interval_sub and an unsigned long seq, and she's ready to spill the tea ☕

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🌸 ARGUMENTS 🌸

• interval_sub — the subscription. that's her. the main character energy of the parameter list 👑
• seq — the return value of the matching mmu_interval_read_begin. like, u have to bring the receipt from the read_begin you did earlier, iykyk 🧾

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💖 DESCRIPTION 💖

okay so here's the moment. this one can be used in the critical section between mmu_interval_read_begin and mmu_interval_read_retry. that's the zone. the arena. the group chat where things get real 🫶

and she can be used as part of loops and other expensive operations to expedite a retry — like a fast little "girl, is this still valid??" check while you're grinding through something heavy 🔥

the way that she can be called many times 😭 yes, spam her, she doesn't mind. she also does not have to hold the user provided lock — she's independent like that, no strings attached ✨

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⭐ RETURN ⭐

• true — an invalidation has collided with this critical region, and a future mmu_interval_read_retry will return true. that's the definitive tea, periodt 🍵👑
• false — not reliable, bestie. it only suggests a collision may not have occurred. so don't be out here trusting false with your life 💀 it's giving "maybe" not "no"

⚠️ real talk: true is solid, false is just a vibe. do not treat false as proof that nothing collided — it's only a hint that a collision may not have occurred. 🙈

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🌈 SEE ALSO 🌈

kernel file ./include/linux/mmu_notifier.h, enum mmu_notifier_event(9), struct mmu_interval_notifier_finish(9), struct mmu_interval_notifier_ops(9), mmu_interval_set_seq(9), mmu_interval_read_retry(9) — go read the whole friend group, they're all connected fr fr 💜

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anyway that's the page! sourced from ./include/linux in October 2026 — mwah, slay, go forth and check those retries 🧚💅💖