SET OF UTILITIES TO DYNAMICALLY COLLECT DEPENDENCIES INTO A(9)

💅 Set of util...ncies into a(9) 💅

Filed under the Kernel API Manual, bestie — this is the page for the set of utilities to dynamically collect dependencies into a structure which is fed into the GT migration code. ✨

Okay so here's the lore: once we can do async unbinding, this is also needed to coalesce the migration fence with the unbind fences if these are coalesced post-migration. 🧚 No cap, that's the whole fence situation.

While collecting the individual dependencies, we store the refcounted struct dma_fence pointers in a realloc-managed pointer array, since that can be easily fed into a dma_fence_array. 🔥 Other options are available, like for example an xarray for similarity with drm/sched. Can be changed easily if needed. 💅

A struct i915_deps need to be initialized using i915_deps_init. 🫶 If i915_deps_add_dependency or i915_deps_add_resv return an error code they will internally call i915_deps_fini, which frees all internal references and allocations. 💖

👀 SEE ALSO 👀

• Kernel file ./drivers/gpu/drm/i915/i915_deps.c
• i915_deps_init(9)
• i915_deps_fini(9)
• i915_deps_sync(9)
• i915_deps_add_dependency(9)
• i915_deps_add_resv(9)

Source/version cutie: ./drivers/gpu/drm/i915 🌸 — dated October 2026. That's the tea, bestie; go collect those dependencies 💖