STRUCT POSIX_CLOCK(9)

💖 struct posix_clock 💖

okay bestie, welcome to the struct posix_clock page — this is the kernel API manual, and we're about to make a dynamic posix clock make sense, no cap ✨

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✨ NAME ✨

struct posix_clock — literally the struct that represents a dynamic posix clock 🕰️

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🎀 SYNOPSIS 🎀

struct posix_clock {
    struct posix_clock_operations ops;
    struct cdev cdev;
    struct device *dev;
    struct rw_semaphore rwsem;
    bool zombie;
 };

yes the closing brace is indented one space in the original, we don't question it, we respect it 💅

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🌸 Members 🌸

• ops — the functional interface to the clock. this is the whole personality of your clock, it's giving main character energy 🫶
• cdev — the character device instance for this clock, iconic as always ✨
• dev — pointer to the clock's device. yeah, just a pointer, lowkey humble of it 🌈
• rwsem — protects the zombie field from concurrent access. it's the bodyguard of one (1) bool and honestly? respect 💅
• zombie — if 'zombie' is true, then the hardware has disappeared 💀 like fr fr, it's gone-gone

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🦋 Description 🦋

so here's the vibe check for driver authors: drivers should embed their struct posix_clock inside a private structure, and then get a reference back to it during callbacks using container_of. classic move, iykyk 🧚

drivers should also supply an initialized but not exposed struct device to posix_clock_register. what's that device for? managing the lifetime of the driver's private structure, periodt ✨ its 'release' field should be set to a release function for this private structure — don't skip that, bestie 🙈

ngl this is the part where people forget to set 'release' and then everything is sad. set it. 🔥

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🌺 SEE ALSO 🌺

• Kernel file ./include/linux/posix-clock.h
• struct posix_clock_operations(9)
• struct posix_clock_context(9)
• posix_clock_register(9)
• posix_clock_unregister(9)

go read posix_clock_unregister(9) too okay, balance is everything 💜

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and that's the page!! sourced from ./include/linux, dated October 2026 — remember us fondly, bestie, mwah 😭💖🎀