[PATCH 4/6] drm/amdgpu: Attach eviction fence on alloc

Errabolu, Ramesh Ramesh.Errabolu at amd.com
Mon Jan 16 22:11:31 UTC 2023


[AMD Official Use Only - General]

Comment inline.

Regards,
Ramesh

-----Original Message-----
From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of Felix Kuehling
Sent: Thursday, January 12, 2023 7:02 AM
To: amd-gfx at lists.freedesktop.org; dri-devel at lists.freedesktop.org
Cc: Chen, Xiaogang <Xiaogang.Chen at amd.com>; Koenig, Christian <Christian.Koenig at amd.com>
Subject: [PATCH 4/6] drm/amdgpu: Attach eviction fence on alloc

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Instead of attaching the eviction fence when a KFD BO is first mapped, attach it when it is allocated or imported. This in preparation to allow KFD BOs to be mapped using the render node API.

Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>
---
 .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c  | 63 ++++++++++---------
 1 file changed, 32 insertions(+), 31 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index 5645103beed0..79213f476493 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -360,6 +360,24 @@ static int amdgpu_amdkfd_bo_validate(struct amdgpu_bo *bo, uint32_t domain,
        return ret;
 }

+static int amdgpu_amdkfd_bo_validate_and_fence(struct amdgpu_bo *bo,
+                                              uint32_t domain,
+                                              struct dma_fence *fence) 
+{
+       int ret = amdgpu_bo_reserve(bo, false);
+
+       if (ret)
+               return ret;
+
+       ret = amdgpu_amdkfd_bo_validate(bo, domain, true);
+       if (!ret)
Ramesh: Should space for fences be reserved before adding one.

+               dma_resv_add_fence(bo->tbo.base.resv, fence,
+                                  DMA_RESV_USAGE_BOOKKEEP);
+       amdgpu_bo_unreserve(bo);
+
+       return ret;
+}
+
 static int amdgpu_amdkfd_validate_vm_bo(void *_unused, struct amdgpu_bo *bo)  {
        return amdgpu_amdkfd_bo_validate(bo, bo->allowed_domains, false); @@ -1720,6 +1738,11 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(
                }
                bo->allowed_domains = AMDGPU_GEM_DOMAIN_GTT;
                bo->preferred_domains = AMDGPU_GEM_DOMAIN_GTT;
+       } else {
+               ret = amdgpu_amdkfd_bo_validate_and_fence(bo, domain,
+                               &avm->process_info->eviction_fence->base);
+               if (ret)
+                       goto err_validate_bo;
        }

        if (offset)
@@ -1729,6 +1752,7 @@ int amdgpu_amdkfd_gpuvm_alloc_memory_of_gpu(

 allocate_init_user_pages_failed:
 err_pin_bo:
+err_validate_bo:
        remove_kgd_mem_from_kfd_bo_list(*mem, avm->process_info);
        drm_vma_node_revoke(&gobj->vma_node, drm_priv);
 err_node_allow:
@@ -1804,10 +1828,6 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu(
        if (unlikely(ret))
                return ret;

-       /* The eviction fence should be removed by the last unmap.
-        * TODO: Log an error condition if the bo still has the eviction fence
-        * attached
-        */
        amdgpu_amdkfd_remove_eviction_fence(mem->bo,
                                        process_info->eviction_fence);
Ramesh: Is it correct to call remove_eviction() unconditionally? This procedure applies to GTT and VRAM BO's only. Furthermore, the fence on these BO's has already been removed in the unmap_memory() call.

        pr_debug("Release VA 0x%llx - 0x%llx\n", mem->va, @@ -1931,19 +1951,6 @@ int amdgpu_amdkfd_gpuvm_map_memory_to_gpu(
        if (unlikely(ret))
                goto out_unreserve;

-       if (mem->mapped_to_gpu_memory == 0 &&
-           !amdgpu_ttm_tt_get_usermm(bo->tbo.ttm)) {
-               /* Validate BO only once. The eviction fence gets added to BO
-                * the first time it is mapped. Validate will wait for all
-                * background evictions to complete.
-                */
-               ret = amdgpu_amdkfd_bo_validate(bo, domain, true);
-               if (ret) {
-                       pr_debug("Validate failed\n");
-                       goto out_unreserve;
-               }
-       }
-
        list_for_each_entry(entry, &mem->attachments, list) {
                if (entry->bo_va->base.vm != avm || entry->is_mapped)
                        continue;
@@ -1970,10 +1977,6 @@ int amdgpu_amdkfd_gpuvm_map_memory_to_gpu(
                         mem->mapped_to_gpu_memory);
        }

-       if (!amdgpu_ttm_tt_get_usermm(bo->tbo.ttm) && !bo->tbo.pin_count)
-               dma_resv_add_fence(bo->tbo.base.resv,
-                                  &avm->process_info->eviction_fence->base,
-                                  DMA_RESV_USAGE_BOOKKEEP);
        ret = unreserve_bo_and_vms(&ctx, false, false);

        goto out;
@@ -1990,7 +1993,6 @@ int amdgpu_amdkfd_gpuvm_unmap_memory_from_gpu(
                struct amdgpu_device *adev, struct kgd_mem *mem, void *drm_priv)  {
        struct amdgpu_vm *avm = drm_priv_to_vm(drm_priv);
-       struct amdkfd_process_info *process_info = avm->process_info;
        unsigned long bo_size = mem->bo->tbo.base.size;
        struct kfd_mem_attachment *entry;
        struct bo_vm_reservation_context ctx; @@ -2031,15 +2033,6 @@ int amdgpu_amdkfd_gpuvm_unmap_memory_from_gpu(
                         mem->mapped_to_gpu_memory);
        }

-       /* If BO is unmapped from all VMs, unfence it. It can be evicted if
-        * required.
-        */
-       if (mem->mapped_to_gpu_memory == 0 &&
-           !amdgpu_ttm_tt_get_usermm(mem->bo->tbo.ttm) &&
-           !mem->bo->tbo.pin_count)
-               amdgpu_amdkfd_remove_eviction_fence(mem->bo,
-                                               process_info->eviction_fence);
-
 unreserve_out:
        unreserve_bo_and_vms(&ctx, false, false);
 out:
@@ -2266,8 +2259,16 @@ int amdgpu_amdkfd_gpuvm_import_dmabuf(struct amdgpu_device *adev,
        amdgpu_sync_create(&(*mem)->sync);
        (*mem)->is_imported = true;

+       ret = amdgpu_amdkfd_bo_validate_and_fence(bo, (*mem)->domain,
+                               &avm->process_info->eviction_fence->base);
+       if (ret)
+               goto err_remove_mem;
+
        return 0;

+err_remove_mem:
+       remove_kgd_mem_from_kfd_bo_list(*mem, avm->process_info);
+       drm_vma_node_revoke(&obj->vma_node, drm_priv);
 err_free_mem:
        kfree(*mem);
 err_put_obj:
--
2.34.1


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