[PATCH 2/2] drm/amdgpu: link shadow bo as well

[Christian König]

Am 24.04.2018 um 09:35 schrieb Chunming Zhou:
> Shadow BO is located on GTT and its parent (PT and PD) BO could located on VRAM.
> In some case, the BO on GTT could be evicted but the parent did not. This may
> cause the shadow BO not be put in the evict list and could not be invalidate
> correctly.
>
> Change-Id: Iad10d9a3031fa2b243879b9e58ee4d8c527eb433
> Signed-off-by: Chunming Zhou <david1.zhou at amd.com>
> Reported-by: Shaoyun Liu <Shaoyun.Liu at amd.com>

Way to much memory usage and to complicated.

What we need to do is just to handle the real BO as evicted when the 
shadow BO is evicted.

Something like the following at the start of amdgpu_vm_bo_invalidate() 
should be sufficient:

if (bo->parent && bo->parent->shadow == bo)
     bo = bo->parent;

Regards,
Christian.


> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c     |  5 -----
>   drivers/gpu/drm/amd/amdgpu/amdgpu_object.h |  1 +
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c     | 11 +++++++++++
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h     |  1 +
>   4 files changed, 13 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> index e1756b68a17b..9c9f6fc5c994 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> @@ -462,11 +462,6 @@ static int amdgpu_cs_validate(void *param, struct amdgpu_bo *bo)
>   	do {
>   		r = amdgpu_cs_bo_validate(p, bo);
>   	} while (r == -ENOMEM && amdgpu_cs_try_evict(p, bo));
> -	if (r)
> -		return r;
> -
> -	if (bo->shadow)
> -		r = amdgpu_cs_bo_validate(p, bo->shadow);
>   
>   	return r;
>   }
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> index 540e03fa159f..8078da36aec7 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
> @@ -58,6 +58,7 @@ struct amdgpu_bo_va_mapping {
>   /* User space allocated BO in a VM */
>   struct amdgpu_bo_va {
>   	struct amdgpu_vm_bo_base	base;
> +	struct amdgpu_vm_bo_base	shadow_base;
>   
>   	/* protected by bo being reserved */
>   	unsigned			ref_count;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index c75b96433ee7..026147cc5104 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -450,8 +450,13 @@ static int amdgpu_vm_alloc_levels(struct amdgpu_device *adev,
>   			pt->parent = amdgpu_bo_ref(parent->base.bo);
>   
>   			amdgpu_vm_bo_base_init(&entry->base, vm, pt);
> +			amdgpu_vm_bo_base_init(&entry->shadow_base, vm,
> +					       pt->shadow);
>   			spin_lock(&vm->status_lock);
>   			list_move(&entry->base.vm_status, &vm->relocated);
> +			if (pt->shadow)
> +				list_move(&entry->shadow_base.vm_status,
> +					  &vm->relocated);
>   			spin_unlock(&vm->status_lock);
>   		}
>   
> @@ -1875,6 +1880,7 @@ struct amdgpu_bo_va *amdgpu_vm_bo_add(struct amdgpu_device *adev,
>   		return NULL;
>   	}
>   	amdgpu_vm_bo_base_init(&bo_va->base, vm, bo);
> +	amdgpu_vm_bo_base_init(&bo_va->shadow_base, vm, bo ? bo->shadow : NULL);
>   
>   	bo_va->ref_count = 1;
>   	INIT_LIST_HEAD(&bo_va->valids);
> @@ -2220,9 +2226,11 @@ void amdgpu_vm_bo_rmv(struct amdgpu_device *adev,
>   	struct amdgpu_vm *vm = bo_va->base.vm;
>   
>   	list_del(&bo_va->base.bo_list);
> +	list_del(&bo_va->shadow_base.bo_list);
>   
>   	spin_lock(&vm->status_lock);
>   	list_del(&bo_va->base.vm_status);
> +	list_del(&bo_va->shadow_base.vm_status);
>   	spin_unlock(&vm->status_lock);
>   
>   	list_for_each_entry_safe(mapping, next, &bo_va->valids, list) {
> @@ -2456,6 +2464,7 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
>   		goto error_unreserve;
>   
>   	amdgpu_vm_bo_base_init(&vm->root.base, vm, root);
> +	amdgpu_vm_bo_base_init(&vm->root.shadow_base, vm, root->shadow);
>   	amdgpu_bo_unreserve(vm->root.base.bo);
>   
>   	if (pasid) {
> @@ -2575,6 +2584,8 @@ static void amdgpu_vm_free_levels(struct amdgpu_device *adev,
>   	if (parent->base.bo) {
>   		list_del(&parent->base.bo_list);
>   		list_del(&parent->base.vm_status);
> +		list_del(&parent->shadow_base.bo_list);
> +		list_del(&parent->shadow_base.vm_status);
>   		amdgpu_bo_unref(&parent->base.bo->shadow);
>   		amdgpu_bo_unref(&parent->base.bo);
>   	}
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> index 30f080364c97..f4ae6c6b28b8 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> @@ -153,6 +153,7 @@ struct amdgpu_vm_bo_base {
>   
>   struct amdgpu_vm_pt {
>   	struct amdgpu_vm_bo_base	base;
> +	struct amdgpu_vm_bo_base	shadow_base;
>   	bool				huge;
>   
>   	/* array of page tables, one for each directory entry */