STRUCT DEV_DAX(9)

💅 struct dev_dax ✨

okay so this is a page straight out of the Kernel API Manual, and it's all about struct dev_dax — no cap, it's a whole vibe. 🦋

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🌸 NAME 🌸

struct dev_dax — the instance data for a subdivision of a dax region, plus the data while the device is activated in the driver. literally the little glow-up corner of a dax region that keeps its own receipts 💖

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✨ SYNOPSIS ✨

struct dev_dax {
    struct dax_region *region;
    struct dax_device *dax_dev;
    u64 cached_size;
    unsigned int align;
    int target_node;
    bool dyn_id;
    int id;
    struct ida ida;
    struct device dev;
    struct dev_pagemap *pgmap;
    bool memmap_on_memory;
    int nr_range;
    struct dev_dax_range *ranges;
};

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🎀 Members 🎀

okay bestie, field-by-field, and yes we're doing all of them 👑

• region — parent region, the main character it belongs to 💫
• dax_dev — core dax functionality
• cached_size — size of daxdev cached by fsdev_dax
• align — alignment of this instance
• target_node — effective numa node if dev_dax memory range is onlined
• dyn_id — is this a dynamic or statically created instance
• id — ida allocated id when the dax_region is not static
• ida — mapping id allocator
• dev — device core
• pgmap — pgmap for memmap setup / lifetime (driver owned)
• memmap_on_memory — allow kmem to put the memmap in the memory
• nr_range — size of ranges
• ranges — range tuples of memory used

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🦋 SEE ALSO 🦋

go peek at these, iykyk 👀

• Kernel file ./drivers/dax/dax-private.h struct dax_region(9), struct dax_mapping(9), struct dev_dax_range(9)

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and that's the whole thing, bestie — periodt 💅✨

source squad, say hi: this one lives in ./drivers/dax, it's dated October 2026, and the page itself is struct dev_dax(9). 🫶🌸