STRUCT FUTEX_MM_DATA(9)

💜 struct futex_mm_data(9) — the Kernel API Manual moment

okay so bestie, welcome to the Kernel API Manual ✨ today we're looking at struct futex_mm_data, and it's literally the per-MM data that futexes keep around. That's it, that's the vibe. 💅

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🌸 NAME 🌸

struct futex_mm_data — Futex related per MM data 🫶

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✨ SYNOPSIS ✨

Like, here's the whole shape of it, no cap:

struct futex_mm_data {
    struct futex_mm_phash           phash;
    struct futex_unlock_cs_ranges   unlock;
    atomic64_t unique_id;
 };

Three members, three little icons, all main character energy 👑

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🎀 Members 🎀

• phash — the futex private hash related data. yes bestie, private hash, it's giving secret little bookkeeping 🌸
• unlock — the futex unlock VDSO critical sections. that's the unlock side of the VDSO crit-section situation, iconic 🔥
• unique_id — the unique ID of the MM, and it's specifically for FUT_OFF_MMSHARED futexes. an atomic64_t too, so it's fr fr out here being atomic 💀✨

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🦋 SEE ALSO 🦋

Kernel file ./include/linux/futex_types.h — plus these besties:

• struct futex_sched_data(9)
• struct futex_mm_phash(9)
• struct futex_unlock_cs_range(9)
• struct futex_unlock_cs_ranges(9)

go read them, iykyk 👀💖

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and that's the whole page, bestie 🏁 sourced from ./include/linux, dated October 2026 — mwah, slay, periodt 💅🎀🌈