Am 28.01.22 um 16:55 schrieb Felix Kuehling:
Am 2022-01-28 um 10:16 schrieb Christian König:
[SNIP]
- if (bo->tbo.resource->mem_type == AMDGPU_PL_PREEMPT) {
As far as I can see, you didn't add this check back elsewhere. The
promise for preemptible BOs is, that we never have to wait for the GPU
to finish accessing the BOs because the context using it is
preemptible. This was a necessary condition to disable GTT usage
accounting for such BOs. If you allow filling such BOs with this
function, you're breaking that promise.
That's now part of amdgpu_ttm_map_buffer(), but unfortunately as
BUG_ON(). I've added a patch to change that into a warning.
[SNIP]
+ cur_size = min_t(u64, dst.size, AMDGPU_GTT_MAX_TRANSFER_BYTES);
For VRAM, the cur_size could be much bigger because we're not limited
by the GART transfer window. I'm pretty sure that 2MB is going to add
too much overhead. For the extreme 60GB BO example, it would require
30-thousand IBs and IB frames to fill the entire buffer. That's a lot
of VMID-switching, IB execution, fence signalling, interrupts, etc.
I've restructured the mapping function so that we can now copy/fill in
256MiB chunks when no GART window is involved.
+
+ r = amdgpu_ttm_map_buffer(&bo->tbo, bo->tbo.resource, &dst,
+ PFN_UP(cur_size), 1, ring, false,
+ &to);
+ if (r)
+ goto error;
+
+ r = amdgpu_ttm_fill_mem(ring, src_data, to, cur_size, resv,
+ &next, false);
If amdgpu_ttm_map_buffer updated the page tables, shouldn't the
vm_needs_flush parameter be true? This flag should probably be
returned by amdgpu_ttm_map_buffer.
Ah, yes. That's indeed a typo. For now I've didn't added the
vm_needs_flush parameter, but that's something we could optimize.
Regards,
Christian.
Regards,
Felix
+ if (r)
+ goto error;
+
+ dma_fence_put(fence);
+ fence = next;
+
+ amdgpu_res_next(&dst, cur_size);
+ }
+error:
+ mutex_unlock(&adev->mman.gtt_window_lock);
+ if (f)
+ *f = dma_fence_get(fence);
+ dma_fence_put(fence);
+ return r;
+}
+
/**
* amdgpu_ttm_evict_resources - evict memory buffers
* @adev: amdgpu device object
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
index d9691f262f16..bcd34592e45d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
@@ -35,6 +35,8 @@
#define AMDGPU_GTT_MAX_TRANSFER_SIZE 512
#define AMDGPU_GTT_NUM_TRANSFER_WINDOWS 2
+#define AMDGPU_GTT_MAX_TRANSFER_BYTES (AMDGPU_GTT_MAX_TRANSFER_SIZE * \
+ AMDGPU_GPU_PAGE_SIZE)
#define AMDGPU_POISON 0xd0bed0be
