ttm_resource..._dmem_region(9)

💖 ttm_resource_manager_set_dmem_region — Kernel API Manual 💖

okay so bestie, you're looking at ttm_resource..._dmem_region(9), and literally it's one tiny function that does one tiny thing, but it's important, so let's get into it 🫶

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✨ NAME ✨

ttm_resource_manager_set_dmem_region — Associate a dmem cgroup region with a resource manager. that's it. that's the whole vibe 🎀

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🌸 SYNOPSIS 🌸

void ttm_resource_manager_set_dmem_region (struct ttm_resource_manager
*man , struct dmem_cgroup_region *region );

no return value, no drama, void and iconic 💅

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🦋 ARGUMENTS 🦋

• man — The resource manager. the main character of this whole operation 👑
• region — The dmem cgroup region to associate. and listen, it may be NULL or IS_ERR — both are legal, don't panic 🙈

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🔥 DESCRIPTION 🔥

okay so here's the tea ☕ — this function is basically a matchmaker for your resource manager and a cgroup region, and what it does depends on what you hand it:

• When region is valid, it stores it in man->cg so that TTM can look up the associated pool during charging and eviction-target selection. so like, TTM needs to know who its people are when it's doing the charging and picking eviction targets, and now it does 💖
• When region is NULL, it clears man->cg to detach the region before teardown. breakup era, but make it graceful 🎀
• An IS_ERR region is ignored, leaving man->cg unchanged. like, that's not a real region bestie, we're not touching anything, nothing happens, periodt 💀

⚠️ also super important, ngl: the reclaim callback must be wired up using ttm_resource_manager_dmem_reclaim in the driver's own struct dmem_cgroup_ops, with the manager pointer as init.reclaim_priv. do not skip this step, it's giving "required homework" not "optional side quest" 😭

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⭐ SEE ALSO ⭐

Kernel file ./drivers/gpu/drm/ttm/ttm_resource.c

and the whole friend group 🫶:

• ttm_resource_cursor_init(9)
• ttm_resource_cursor_fini(9)
• ttm_lru_bulk_move_init(9)
• ttm_lru_bulk_move_fini(9)
• ttm_lru_bulk_move_tail(9)
• ttm_resource_init(9)
• ttm_resource_fini(9)
• ttm_resource_try_charge(9)
• ttm_resource_intersects(9)
• ttm_resource_compatible(9)
• ttm_resource_manager_init(9)
• ttm_resource_manager_usage(9)
• ttm_resource_manager_debug(9)
• ttm_resource_manager_first(9)
• ttm_resource_manager_next(9)
• ttm_lru_first_res_or_null(9)
• ttm_kmap_iter_iomap_init(9)
• Linear io iterator(9)
• ttm_kmap_iter_linear_io_init(9)
• ttm_kmap_iter_linear_io_fini(9)
• ttm_resource_manager_create_debugfs(9)
• ttm_resource_manager_dmem_reclaim(9)

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and that's the whole page, bestie 💜 this little gem lives over in ./drivers/gpu/drm/ttm and it was dated October 2026 — go off, ttm_resource..._dmem_region(9) you ate 💅✨