STRUCT TTM_RESOURCE_MANAGER(9)

💅 struct ttm_resource_manager(9)

okay so this is a page from the Kernel API Manual bestie, and it's literally all about struct ttm_resource_manager — the lil' main character that keeps track of memory types for a device. no cap, it's giving "backstage manager of the whole memory vibe." let's get into it 🎀

✨ SYNOPSIS ✨

struct ttm_resource_manager {
    bool use_type;
    bool use_tt;
    struct ttm_device *bdev;
    uint64_t size;
    const struct ttm_resource_manager_func *func;
    spinlock_t eviction_lock;
    struct dma_fence *eviction_fences[TTM_NUM_MOVE_FENCES];
    struct list_head lru[TTM_MAX_BO_PRIORITY];
    uint64_t usage;
    struct dmem_cgroup_region *cg;
 };

🌸 Members 🌸

• use_type — this bool is the vibe check for the memory type: it's enabled or it's not, periodt. ✨
• use_tt — says whether a TT object should be the backing store for this thing. iykyk.
• bdev — the ttm device that this manager belongs to 🫶 (its home base, fr fr).
• size — how big the managed region is. the actual size. the whole thing 💖
• func — a structure pointer implementing the range manager. see above, bestie 👆
• eviction_lock — the lock for eviction fences 🔒 literally its whole job.
• eviction_fences — the fences of the last pipelined move operation. yes, all of them, it's an array: eviction_fences[TTM_NUM_MOVE_FENCES] 🦋
• lru — the lru list for this memory type, and it's an array too: lru[TTM_MAX_BO_PRIORITY] 🎀
• usage — how much of the resources are used. important caveat: this is protected by bdev->lru_lock 🔥 don't be out here reading it unprotected, that's not the move 💀
• cg — the dmem_cgroup_region used for memory accounting, if it's not NULL. if it is NULL, bestie, there's no accounting happening 🙈

⭐ Description ⭐

so like, this structure is used to identify and manage memory types for a device ✨ that's it, that's the whole glow-up. it's the organizational queen of the memory types 👑

🦋 SEE ALSO 🦋

kernel file ./include/drm/ttm/ttm_resource.h and honestly this whole friend group:

• TTM_NUM_MOVE_FENCES(9)
• enum ttm_lru_item_type(9)
• struct ttm_lru_item(9)
• ttm_lru_item_init(9)
• struct ttm_bus_placement(9)
• struct ttm_resource(9)
• ttm_lru_item_to_res(9)
• struct ttm_lru_bulk_move_pos(9)
• struct ttm_lru_bulk_move(9)
• struct ttm_resource_cursor(9)
• struct ttm_kmap_iter_iomap(9)
• struct ttm_kmap_iter_linear_io(9)
• ttm_resource_manager_set_used(9)
• ttm_resource_manager_used(9)
• ttm_resource_manager_cleanup(9)
• ttm_resource_manager_for_each_res(9)

and that's the whole page!! 🧚 from ./include/drm/ttm, dated October 2026 — mwah, slay, go read the source header if you want more 💜👑