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* [RFC PATCH v2] drm/amdgpu: Remove kfd eviction fence before release bo
@ 2020-02-07 13:42 Pan, Xinhui
  2020-02-07 13:46 ` Christian König
  0 siblings, 1 reply; 4+ messages in thread
From: Pan, Xinhui @ 2020-02-07 13:42 UTC (permalink / raw)
  To: amd-gfx; +Cc: Deucher, Alexander, Kuehling, Felix, Koenig, Christian

No need to trigger eviction as the memory mapping will not be used anymore.

All pt/pd bos share same resv, hence the same shared eviction fence. Everytime page table is freed, the fence will be signled and that cuases kfd unexcepted evictions.

Signed-off-by: xinhui pab <xinhui.pan@example.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h    |  1 +
 .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c  | 78 ++++++++++++++++++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.c    | 10 ++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c        |  5 +-
 drivers/gpu/drm/ttm/ttm_bo.c                  | 38 +++++----
 5 files changed, 111 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
index 47b0f2957d1f..265b1ed7264c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
@@ -96,6 +96,7 @@ struct amdgpu_amdkfd_fence *amdgpu_amdkfd_fence_create(u64 context,
 						       struct mm_struct *mm);
 bool amdkfd_fence_check_mm(struct dma_fence *f, struct mm_struct *mm);
 struct amdgpu_amdkfd_fence *to_amdgpu_amdkfd_fence(struct dma_fence *f);
+int amdgpu_amdkfd_remove_fence_on_pt_pd_bos(struct amdgpu_bo *bo);
 
 struct amdkfd_process_info {
 	/* List head of all VMs that belong to a KFD process */
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index ef721cb65868..11315095c29b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -223,7 +223,7 @@ void amdgpu_amdkfd_unreserve_memory_limit(struct amdgpu_bo *bo)
 static int amdgpu_amdkfd_remove_eviction_fence(struct amdgpu_bo *bo,
 					struct amdgpu_amdkfd_fence *ef)
 {
-	struct dma_resv *resv = bo->tbo.base.resv;
+	struct dma_resv *resv = &bo->tbo.base._resv;
 	struct dma_resv_list *old, *new;
 	unsigned int i, j, k;
 
@@ -276,6 +276,78 @@ static int amdgpu_amdkfd_remove_eviction_fence(struct amdgpu_bo *bo,
 	return 0;
 }
 
+int amdgpu_amdkfd_remove_fence_on_pt_pd_bos(struct amdgpu_bo *bo)
+{
+	struct amdgpu_vm_bo_base        *vm_bo = bo->vm_bo;
+	struct amdgpu_vm *vm;
+	struct amdkfd_process_info *info;
+	struct amdgpu_amdkfd_fence *ef;
+	struct amdgpu_bo *parent;
+	int locked;
+	int ret;
+	struct ttm_bo_global *glob = &ttm_bo_glob;
+
+	if (vm_bo == NULL)
+		return 0;
+
+	/* Page table bo has a reference of the parent bo.
+	 * BO itself can't guarntee the vm it points to is alive.
+	 * for example, VM is going to free page tables, and the pt/pd bo might be
+	 * freed by a workqueue. In that case, the vm might be freed already,
+	 * leaving the bo->vm_bo points to vm.root.
+	 *
+	 * so to avoid that, when kfd free its vms,
+	 * 1) set vm->process_info to NULL if this is the last vm.
+	 * 2) set root_bo->vm_bo to NULL.
+	 *
+	 * but there are still races, just like
+	 * cpu 1 		cpu 2
+	 * 			!vm_bo
+	 * ->info = NULL
+	 * free(info)
+	 * ->vm_bo = NULL
+	 * free (vm)
+	 * 			info = vm->info //invalid vm
+	 *
+	 * So to avoid the race, use ttm_bo_glob lru_lock.
+	 * generally speaking, adding a new lock is accceptable.
+	 * But reusing this lock is simple.
+	 */
+	parent = bo;
+	while (parent->parent)
+		parent = parent->parent;
+
+	spin_lock(&glob->lru_lock);
+	vm_bo = parent->vm_bo;
+	if (!vm_bo) {
+		spin_unlock(&glob->lru_lock);
+		return 0;
+	}
+
+	vm = vm_bo->vm;
+	if (!vm) {
+		spin_unlock(&glob->lru_lock);
+		return 0;
+	}
+
+	info = vm->process_info;
+	if (!info || !info->eviction_fence) {
+		spin_unlock(&glob->lru_lock);
+		return 0;
+	}
+
+	ef = container_of(dma_fence_get(&info->eviction_fence->base),
+			struct amdgpu_amdkfd_fence, base);
+	spin_unlock(&glob->lru_lock);
+
+	locked = dma_resv_trylock(&bo->tbo.base._resv);
+	ret = amdgpu_amdkfd_remove_eviction_fence(bo, ef);
+	dma_fence_put(&ef->base);
+	if (locked)
+		dma_resv_unlock(&bo->tbo.base._resv);
+	return ret;
+}
+
 static int amdgpu_amdkfd_bo_validate(struct amdgpu_bo *bo, uint32_t domain,
 				     bool wait)
 {
@@ -1030,6 +1102,7 @@ void amdgpu_amdkfd_gpuvm_destroy_cb(struct amdgpu_device *adev,
 {
 	struct amdkfd_process_info *process_info = vm->process_info;
 	struct amdgpu_bo *pd = vm->root.base.bo;
+	struct ttm_bo_global *glob = &ttm_bo_glob;
 
 	if (!process_info)
 		return;
@@ -1051,6 +1124,9 @@ void amdgpu_amdkfd_gpuvm_destroy_cb(struct amdgpu_device *adev,
 		WARN_ON(!list_empty(&process_info->userptr_valid_list));
 		WARN_ON(!list_empty(&process_info->userptr_inval_list));
 
+		spin_lock(&glob->lru_lock);
+		vm->process_info = NULL;
+		spin_unlock(&glob->lru_lock);
 		dma_fence_put(&process_info->eviction_fence->base);
 		cancel_delayed_work_sync(&process_info->restore_userptr_work);
 		put_pid(process_info->pid);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index 6f60a581e3ba..6ad12298fa84 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -1307,19 +1307,23 @@ void amdgpu_bo_release_notify(struct ttm_buffer_object *bo)
 	if (abo->kfd_bo)
 		amdgpu_amdkfd_unreserve_memory_limit(abo);
 
+	amdgpu_amdkfd_remove_fence_on_pt_pd_bos(abo);
+	abo->vm_bo = NULL;
+
 	if (bo->mem.mem_type != TTM_PL_VRAM || !bo->mem.mm_node ||
 	    !(abo->flags & AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE))
 		return;
 
-	dma_resv_lock(bo->base.resv, NULL);
+	/* Only kfd bo wipe vram on release. The resv is &_resv. */
+	dma_resv_lock(&bo->base._resv, NULL);
 
-	r = amdgpu_fill_buffer(abo, AMDGPU_POISON, bo->base.resv, &fence);
+	r = amdgpu_fill_buffer(abo, AMDGPU_POISON, &bo->base._resv, &fence);
 	if (!WARN_ON(r)) {
 		amdgpu_bo_fence(abo, fence, false);
 		dma_fence_put(fence);
 	}
 
-	dma_resv_unlock(bo->base.resv);
+	dma_resv_unlock(&bo->base._resv);
 }
 
 /**
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index cc56eaba1911..2b96447e30e5 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -945,7 +945,6 @@ static int amdgpu_vm_alloc_pts(struct amdgpu_device *adev,
 static void amdgpu_vm_free_table(struct amdgpu_vm_pt *entry)
 {
 	if (entry->base.bo) {
-		entry->base.bo->vm_bo = NULL;
 		list_del(&entry->base.vm_status);
 		amdgpu_bo_unref(&entry->base.bo->shadow);
 		amdgpu_bo_unref(&entry->base.bo);
@@ -3074,6 +3073,7 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 	struct amdgpu_bo_va_mapping *mapping, *tmp;
 	bool prt_fini_needed = !!adev->gmc.gmc_funcs->set_prt;
 	struct amdgpu_bo *root;
+	struct ttm_bo_global *glob = &ttm_bo_glob;
 	int i;
 
 	amdgpu_amdkfd_gpuvm_destroy_cb(adev, vm);
@@ -3105,6 +3105,9 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 	}
 
 	amdgpu_vm_free_pts(adev, vm, NULL);
+	spin_lock(&glob->lru_lock);
+	root->vm_bo = NULL;
+	spin_unlock(&glob->lru_lock);
 	amdgpu_bo_unreserve(root);
 	amdgpu_bo_unref(&root);
 	WARN_ON(vm->root.base.bo);
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 1494aebb8128..706cd60eb9e0 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -429,8 +429,8 @@ static int ttm_bo_individualize_resv(struct ttm_buffer_object *bo)
 	BUG_ON(!dma_resv_trylock(&bo->base._resv));
 
 	r = dma_resv_copy_fences(&bo->base._resv, bo->base.resv);
-	if (r)
-		dma_resv_unlock(&bo->base._resv);
+
+	dma_resv_unlock(&bo->base._resv);
 
 	return r;
 }
@@ -455,23 +455,19 @@ static void ttm_bo_flush_all_fences(struct ttm_buffer_object *bo)
 	}
 }
 
-static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)
+static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo, bool enqueue)
 {
 	struct ttm_bo_device *bdev = bo->bdev;
 	int ret;
 
-	ret = ttm_bo_individualize_resv(bo);
-	if (ret) {
-		/* Last resort, if we fail to allocate memory for the
-		 * fences block for the BO to become idle
-		 */
-		dma_resv_wait_timeout_rcu(bo->base.resv, true, false,
-						    30 * HZ);
-		spin_lock(&ttm_bo_glob.lru_lock);
-		goto error;
-	}
-
 	spin_lock(&ttm_bo_glob.lru_lock);
+
+	if (enqueue)
+		goto queue;
+
+	if (bo->base.resv != &bo->base._resv)
+		BUG_ON(!dma_resv_trylock(&bo->base._resv));
+
 	ret = dma_resv_trylock(bo->base.resv) ? 0 : -EBUSY;
 	if (!ret) {
 		if (dma_resv_test_signaled_rcu(&bo->base._resv, true)) {
@@ -504,7 +500,7 @@ static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)
 		dma_resv_unlock(&bo->base._resv);
 	}
 
-error:
+queue:
 	kref_get(&bo->list_kref);
 	list_add_tail(&bo->ddestroy, &bdev->ddestroy);
 	spin_unlock(&ttm_bo_glob.lru_lock);
@@ -655,6 +651,16 @@ static void ttm_bo_release(struct kref *kref)
 	    container_of(kref, struct ttm_buffer_object, kref);
 	struct ttm_bo_device *bdev = bo->bdev;
 	struct ttm_mem_type_manager *man = &bdev->man[bo->mem.mem_type];
+	int ret;
+
+	ret = ttm_bo_individualize_resv(bo);
+	if (ret) {
+		/* Last resort, if we fail to allocate memory for the
+		 * fences block for the BO to become idle
+		 */
+		dma_resv_wait_timeout_rcu(bo->base.resv, true, false,
+				30 * HZ);
+	}
 
 	if (bo->bdev->driver->release_notify)
 		bo->bdev->driver->release_notify(bo);
@@ -663,7 +669,7 @@ static void ttm_bo_release(struct kref *kref)
 	ttm_mem_io_lock(man, false);
 	ttm_mem_io_free_vm(bo);
 	ttm_mem_io_unlock(man);
-	ttm_bo_cleanup_refs_or_queue(bo);
+	ttm_bo_cleanup_refs_or_queue(bo, !!ret);
 	kref_put(&bo->list_kref, ttm_bo_release_list);
 }
 
-- 
2.17.1
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amd-gfx@lists.freedesktop.org
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^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [RFC PATCH v2] drm/amdgpu: Remove kfd eviction fence before release bo
  2020-02-07 13:42 [RFC PATCH v2] drm/amdgpu: Remove kfd eviction fence before release bo Pan, Xinhui
@ 2020-02-07 13:46 ` Christian König
  2020-02-07 13:50   ` 回复: " Pan, Xinhui
  0 siblings, 1 reply; 4+ messages in thread
From: Christian König @ 2020-02-07 13:46 UTC (permalink / raw)
  To: Pan, Xinhui, amd-gfx; +Cc: Deucher, Alexander, Kuehling, Felix

Am 07.02.20 um 14:42 schrieb Pan, Xinhui:
> No need to trigger eviction as the memory mapping will not be used anymore.
>
> All pt/pd bos share same resv, hence the same shared eviction fence. Everytime page table is freed, the fence will be signled and that cuases kfd unexcepted evictions.
>
> Signed-off-by: xinhui pab <xinhui.pan@example.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h    |  1 +
>   .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c  | 78 ++++++++++++++++++-
>   drivers/gpu/drm/amd/amdgpu/amdgpu_object.c    | 10 ++-
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c        |  5 +-
>   drivers/gpu/drm/ttm/ttm_bo.c                  | 38 +++++----
>   5 files changed, 111 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
> index 47b0f2957d1f..265b1ed7264c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
> @@ -96,6 +96,7 @@ struct amdgpu_amdkfd_fence *amdgpu_amdkfd_fence_create(u64 context,
>   						       struct mm_struct *mm);
>   bool amdkfd_fence_check_mm(struct dma_fence *f, struct mm_struct *mm);
>   struct amdgpu_amdkfd_fence *to_amdgpu_amdkfd_fence(struct dma_fence *f);
> +int amdgpu_amdkfd_remove_fence_on_pt_pd_bos(struct amdgpu_bo *bo);
>   
>   struct amdkfd_process_info {
>   	/* List head of all VMs that belong to a KFD process */
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> index ef721cb65868..11315095c29b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> @@ -223,7 +223,7 @@ void amdgpu_amdkfd_unreserve_memory_limit(struct amdgpu_bo *bo)
>   static int amdgpu_amdkfd_remove_eviction_fence(struct amdgpu_bo *bo,
>   					struct amdgpu_amdkfd_fence *ef)
>   {
> -	struct dma_resv *resv = bo->tbo.base.resv;
> +	struct dma_resv *resv = &bo->tbo.base._resv;

That won't work either and probably break a bunch of other cases.

Christian.

>   	struct dma_resv_list *old, *new;
>   	unsigned int i, j, k;
>   
> @@ -276,6 +276,78 @@ static int amdgpu_amdkfd_remove_eviction_fence(struct amdgpu_bo *bo,
>   	return 0;
>   }
>   
> +int amdgpu_amdkfd_remove_fence_on_pt_pd_bos(struct amdgpu_bo *bo)
> +{
> +	struct amdgpu_vm_bo_base        *vm_bo = bo->vm_bo;
> +	struct amdgpu_vm *vm;
> +	struct amdkfd_process_info *info;
> +	struct amdgpu_amdkfd_fence *ef;
> +	struct amdgpu_bo *parent;
> +	int locked;
> +	int ret;
> +	struct ttm_bo_global *glob = &ttm_bo_glob;
> +
> +	if (vm_bo == NULL)
> +		return 0;
> +
> +	/* Page table bo has a reference of the parent bo.
> +	 * BO itself can't guarntee the vm it points to is alive.
> +	 * for example, VM is going to free page tables, and the pt/pd bo might be
> +	 * freed by a workqueue. In that case, the vm might be freed already,
> +	 * leaving the bo->vm_bo points to vm.root.
> +	 *
> +	 * so to avoid that, when kfd free its vms,
> +	 * 1) set vm->process_info to NULL if this is the last vm.
> +	 * 2) set root_bo->vm_bo to NULL.
> +	 *
> +	 * but there are still races, just like
> +	 * cpu 1 		cpu 2
> +	 * 			!vm_bo
> +	 * ->info = NULL
> +	 * free(info)
> +	 * ->vm_bo = NULL
> +	 * free (vm)
> +	 * 			info = vm->info //invalid vm
> +	 *
> +	 * So to avoid the race, use ttm_bo_glob lru_lock.
> +	 * generally speaking, adding a new lock is accceptable.
> +	 * But reusing this lock is simple.
> +	 */
> +	parent = bo;
> +	while (parent->parent)
> +		parent = parent->parent;
> +
> +	spin_lock(&glob->lru_lock);
> +	vm_bo = parent->vm_bo;
> +	if (!vm_bo) {
> +		spin_unlock(&glob->lru_lock);
> +		return 0;
> +	}
> +
> +	vm = vm_bo->vm;
> +	if (!vm) {
> +		spin_unlock(&glob->lru_lock);
> +		return 0;
> +	}
> +
> +	info = vm->process_info;
> +	if (!info || !info->eviction_fence) {
> +		spin_unlock(&glob->lru_lock);
> +		return 0;
> +	}
> +
> +	ef = container_of(dma_fence_get(&info->eviction_fence->base),
> +			struct amdgpu_amdkfd_fence, base);
> +	spin_unlock(&glob->lru_lock);
> +
> +	locked = dma_resv_trylock(&bo->tbo.base._resv);
> +	ret = amdgpu_amdkfd_remove_eviction_fence(bo, ef);
> +	dma_fence_put(&ef->base);
> +	if (locked)
> +		dma_resv_unlock(&bo->tbo.base._resv);
> +	return ret;
> +}
> +
>   static int amdgpu_amdkfd_bo_validate(struct amdgpu_bo *bo, uint32_t domain,
>   				     bool wait)
>   {
> @@ -1030,6 +1102,7 @@ void amdgpu_amdkfd_gpuvm_destroy_cb(struct amdgpu_device *adev,
>   {
>   	struct amdkfd_process_info *process_info = vm->process_info;
>   	struct amdgpu_bo *pd = vm->root.base.bo;
> +	struct ttm_bo_global *glob = &ttm_bo_glob;
>   
>   	if (!process_info)
>   		return;
> @@ -1051,6 +1124,9 @@ void amdgpu_amdkfd_gpuvm_destroy_cb(struct amdgpu_device *adev,
>   		WARN_ON(!list_empty(&process_info->userptr_valid_list));
>   		WARN_ON(!list_empty(&process_info->userptr_inval_list));
>   
> +		spin_lock(&glob->lru_lock);
> +		vm->process_info = NULL;
> +		spin_unlock(&glob->lru_lock);
>   		dma_fence_put(&process_info->eviction_fence->base);
>   		cancel_delayed_work_sync(&process_info->restore_userptr_work);
>   		put_pid(process_info->pid);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> index 6f60a581e3ba..6ad12298fa84 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> @@ -1307,19 +1307,23 @@ void amdgpu_bo_release_notify(struct ttm_buffer_object *bo)
>   	if (abo->kfd_bo)
>   		amdgpu_amdkfd_unreserve_memory_limit(abo);
>   
> +	amdgpu_amdkfd_remove_fence_on_pt_pd_bos(abo);
> +	abo->vm_bo = NULL;
> +
>   	if (bo->mem.mem_type != TTM_PL_VRAM || !bo->mem.mm_node ||
>   	    !(abo->flags & AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE))
>   		return;
>   
> -	dma_resv_lock(bo->base.resv, NULL);
> +	/* Only kfd bo wipe vram on release. The resv is &_resv. */
> +	dma_resv_lock(&bo->base._resv, NULL);
>   
> -	r = amdgpu_fill_buffer(abo, AMDGPU_POISON, bo->base.resv, &fence);
> +	r = amdgpu_fill_buffer(abo, AMDGPU_POISON, &bo->base._resv, &fence);
>   	if (!WARN_ON(r)) {
>   		amdgpu_bo_fence(abo, fence, false);
>   		dma_fence_put(fence);
>   	}
>   
> -	dma_resv_unlock(bo->base.resv);
> +	dma_resv_unlock(&bo->base._resv);
>   }
>   
>   /**
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index cc56eaba1911..2b96447e30e5 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -945,7 +945,6 @@ static int amdgpu_vm_alloc_pts(struct amdgpu_device *adev,
>   static void amdgpu_vm_free_table(struct amdgpu_vm_pt *entry)
>   {
>   	if (entry->base.bo) {
> -		entry->base.bo->vm_bo = NULL;
>   		list_del(&entry->base.vm_status);
>   		amdgpu_bo_unref(&entry->base.bo->shadow);
>   		amdgpu_bo_unref(&entry->base.bo);
> @@ -3074,6 +3073,7 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
>   	struct amdgpu_bo_va_mapping *mapping, *tmp;
>   	bool prt_fini_needed = !!adev->gmc.gmc_funcs->set_prt;
>   	struct amdgpu_bo *root;
> +	struct ttm_bo_global *glob = &ttm_bo_glob;
>   	int i;
>   
>   	amdgpu_amdkfd_gpuvm_destroy_cb(adev, vm);
> @@ -3105,6 +3105,9 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
>   	}
>   
>   	amdgpu_vm_free_pts(adev, vm, NULL);
> +	spin_lock(&glob->lru_lock);
> +	root->vm_bo = NULL;
> +	spin_unlock(&glob->lru_lock);
>   	amdgpu_bo_unreserve(root);
>   	amdgpu_bo_unref(&root);
>   	WARN_ON(vm->root.base.bo);
> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
> index 1494aebb8128..706cd60eb9e0 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
> @@ -429,8 +429,8 @@ static int ttm_bo_individualize_resv(struct ttm_buffer_object *bo)
>   	BUG_ON(!dma_resv_trylock(&bo->base._resv));
>   
>   	r = dma_resv_copy_fences(&bo->base._resv, bo->base.resv);
> -	if (r)
> -		dma_resv_unlock(&bo->base._resv);
> +
> +	dma_resv_unlock(&bo->base._resv);
>   
>   	return r;
>   }
> @@ -455,23 +455,19 @@ static void ttm_bo_flush_all_fences(struct ttm_buffer_object *bo)
>   	}
>   }
>   
> -static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)
> +static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo, bool enqueue)
>   {
>   	struct ttm_bo_device *bdev = bo->bdev;
>   	int ret;
>   
> -	ret = ttm_bo_individualize_resv(bo);
> -	if (ret) {
> -		/* Last resort, if we fail to allocate memory for the
> -		 * fences block for the BO to become idle
> -		 */
> -		dma_resv_wait_timeout_rcu(bo->base.resv, true, false,
> -						    30 * HZ);
> -		spin_lock(&ttm_bo_glob.lru_lock);
> -		goto error;
> -	}
> -
>   	spin_lock(&ttm_bo_glob.lru_lock);
> +
> +	if (enqueue)
> +		goto queue;
> +
> +	if (bo->base.resv != &bo->base._resv)
> +		BUG_ON(!dma_resv_trylock(&bo->base._resv));
> +
>   	ret = dma_resv_trylock(bo->base.resv) ? 0 : -EBUSY;
>   	if (!ret) {
>   		if (dma_resv_test_signaled_rcu(&bo->base._resv, true)) {
> @@ -504,7 +500,7 @@ static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)
>   		dma_resv_unlock(&bo->base._resv);
>   	}
>   
> -error:
> +queue:
>   	kref_get(&bo->list_kref);
>   	list_add_tail(&bo->ddestroy, &bdev->ddestroy);
>   	spin_unlock(&ttm_bo_glob.lru_lock);
> @@ -655,6 +651,16 @@ static void ttm_bo_release(struct kref *kref)
>   	    container_of(kref, struct ttm_buffer_object, kref);
>   	struct ttm_bo_device *bdev = bo->bdev;
>   	struct ttm_mem_type_manager *man = &bdev->man[bo->mem.mem_type];
> +	int ret;
> +
> +	ret = ttm_bo_individualize_resv(bo);
> +	if (ret) {
> +		/* Last resort, if we fail to allocate memory for the
> +		 * fences block for the BO to become idle
> +		 */
> +		dma_resv_wait_timeout_rcu(bo->base.resv, true, false,
> +				30 * HZ);
> +	}
>   
>   	if (bo->bdev->driver->release_notify)
>   		bo->bdev->driver->release_notify(bo);
> @@ -663,7 +669,7 @@ static void ttm_bo_release(struct kref *kref)
>   	ttm_mem_io_lock(man, false);
>   	ttm_mem_io_free_vm(bo);
>   	ttm_mem_io_unlock(man);
> -	ttm_bo_cleanup_refs_or_queue(bo);
> +	ttm_bo_cleanup_refs_or_queue(bo, !!ret);
>   	kref_put(&bo->list_kref, ttm_bo_release_list);
>   }
>   

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^ permalink raw reply	[flat|nested] 4+ messages in thread

* 回复: [RFC PATCH v2] drm/amdgpu: Remove kfd eviction fence before release bo
  2020-02-07 13:46 ` Christian König
@ 2020-02-07 13:50   ` Pan, Xinhui
  2020-02-07 13:52     ` Christian König
  0 siblings, 1 reply; 4+ messages in thread
From: Pan, Xinhui @ 2020-02-07 13:50 UTC (permalink / raw)
  To: Koenig, Christian, amd-gfx; +Cc: Deucher, Alexander, Kuehling, Felix

[AMD Official Use Only - Internal Distribution Only]

________________________________________
发件人: Koenig, Christian <Christian.Koenig@amd.com>
发送时间: 2020年2月7日 21:46
收件人: Pan, Xinhui; amd-gfx@lists.freedesktop.org
抄送: Kuehling, Felix; Deucher, Alexander
主题: Re: [RFC PATCH v2] drm/amdgpu: Remove kfd eviction fence before release bo

Am 07.02.20 um 14:42 schrieb Pan, Xinhui:
> No need to trigger eviction as the memory mapping will not be used anymore.
>
> All pt/pd bos share same resv, hence the same shared eviction fence. Everytime page table is freed, the fence will be signled and that cuases kfd unexcepted evictions.
>
> Signed-off-by: xinhui pab <xinhui.pan@example.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h    |  1 +
>   .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c  | 78 ++++++++++++++++++-
>   drivers/gpu/drm/amd/amdgpu/amdgpu_object.c    | 10 ++-
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c        |  5 +-
>   drivers/gpu/drm/ttm/ttm_bo.c                  | 38 +++++----
>   5 files changed, 111 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
> index 47b0f2957d1f..265b1ed7264c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
> @@ -96,6 +96,7 @@ struct amdgpu_amdkfd_fence *amdgpu_amdkfd_fence_create(u64 context,
>                                                      struct mm_struct *mm);
>   bool amdkfd_fence_check_mm(struct dma_fence *f, struct mm_struct *mm);
>   struct amdgpu_amdkfd_fence *to_amdgpu_amdkfd_fence(struct dma_fence *f);
> +int amdgpu_amdkfd_remove_fence_on_pt_pd_bos(struct amdgpu_bo *bo);
>
>   struct amdkfd_process_info {
>       /* List head of all VMs that belong to a KFD process */
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> index ef721cb65868..11315095c29b 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> @@ -223,7 +223,7 @@ void amdgpu_amdkfd_unreserve_memory_limit(struct amdgpu_bo *bo)
>   static int amdgpu_amdkfd_remove_eviction_fence(struct amdgpu_bo *bo,
>                                       struct amdgpu_amdkfd_fence *ef)
>   {
> -     struct dma_resv *resv = bo->tbo.base.resv;
> +     struct dma_resv *resv = &bo->tbo.base._resv;

That won't work either and probably break a bunch of other cases.

[xh] kfd bos which are allocated explicitly use _resv AFAIK.
only pt/pd bos share the root._resv

Christian.

>       struct dma_resv_list *old, *new;
>       unsigned int i, j, k;
>
> @@ -276,6 +276,78 @@ static int amdgpu_amdkfd_remove_eviction_fence(struct amdgpu_bo *bo,
>       return 0;
>   }
>
> +int amdgpu_amdkfd_remove_fence_on_pt_pd_bos(struct amdgpu_bo *bo)
> +{
> +     struct amdgpu_vm_bo_base        *vm_bo = bo->vm_bo;
> +     struct amdgpu_vm *vm;
> +     struct amdkfd_process_info *info;
> +     struct amdgpu_amdkfd_fence *ef;
> +     struct amdgpu_bo *parent;
> +     int locked;
> +     int ret;
> +     struct ttm_bo_global *glob = &ttm_bo_glob;
> +
> +     if (vm_bo == NULL)
> +             return 0;
> +
> +     /* Page table bo has a reference of the parent bo.
> +      * BO itself can't guarntee the vm it points to is alive.
> +      * for example, VM is going to free page tables, and the pt/pd bo might be
> +      * freed by a workqueue. In that case, the vm might be freed already,
> +      * leaving the bo->vm_bo points to vm.root.
> +      *
> +      * so to avoid that, when kfd free its vms,
> +      * 1) set vm->process_info to NULL if this is the last vm.
> +      * 2) set root_bo->vm_bo to NULL.
> +      *
> +      * but there are still races, just like
> +      * cpu 1                cpu 2
> +      *                      !vm_bo
> +      * ->info = NULL
> +      * free(info)
> +      * ->vm_bo = NULL
> +      * free (vm)
> +      *                      info = vm->info //invalid vm
> +      *
> +      * So to avoid the race, use ttm_bo_glob lru_lock.
> +      * generally speaking, adding a new lock is accceptable.
> +      * But reusing this lock is simple.
> +      */
> +     parent = bo;
> +     while (parent->parent)
> +             parent = parent->parent;
> +
> +     spin_lock(&glob->lru_lock);
> +     vm_bo = parent->vm_bo;
> +     if (!vm_bo) {
> +             spin_unlock(&glob->lru_lock);
> +             return 0;
> +     }
> +
> +     vm = vm_bo->vm;
> +     if (!vm) {
> +             spin_unlock(&glob->lru_lock);
> +             return 0;
> +     }
> +
> +     info = vm->process_info;
> +     if (!info || !info->eviction_fence) {
> +             spin_unlock(&glob->lru_lock);
> +             return 0;
> +     }
> +
> +     ef = container_of(dma_fence_get(&info->eviction_fence->base),
> +                     struct amdgpu_amdkfd_fence, base);
> +     spin_unlock(&glob->lru_lock);
> +
> +     locked = dma_resv_trylock(&bo->tbo.base._resv);
> +     ret = amdgpu_amdkfd_remove_eviction_fence(bo, ef);
> +     dma_fence_put(&ef->base);
> +     if (locked)
> +             dma_resv_unlock(&bo->tbo.base._resv);
> +     return ret;
> +}
> +
>   static int amdgpu_amdkfd_bo_validate(struct amdgpu_bo *bo, uint32_t domain,
>                                    bool wait)
>   {
> @@ -1030,6 +1102,7 @@ void amdgpu_amdkfd_gpuvm_destroy_cb(struct amdgpu_device *adev,
>   {
>       struct amdkfd_process_info *process_info = vm->process_info;
>       struct amdgpu_bo *pd = vm->root.base.bo;
> +     struct ttm_bo_global *glob = &ttm_bo_glob;
>
>       if (!process_info)
>               return;
> @@ -1051,6 +1124,9 @@ void amdgpu_amdkfd_gpuvm_destroy_cb(struct amdgpu_device *adev,
>               WARN_ON(!list_empty(&process_info->userptr_valid_list));
>               WARN_ON(!list_empty(&process_info->userptr_inval_list));
>
> +             spin_lock(&glob->lru_lock);
> +             vm->process_info = NULL;
> +             spin_unlock(&glob->lru_lock);
>               dma_fence_put(&process_info->eviction_fence->base);
>               cancel_delayed_work_sync(&process_info->restore_userptr_work);
>               put_pid(process_info->pid);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> index 6f60a581e3ba..6ad12298fa84 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
> @@ -1307,19 +1307,23 @@ void amdgpu_bo_release_notify(struct ttm_buffer_object *bo)
>       if (abo->kfd_bo)
>               amdgpu_amdkfd_unreserve_memory_limit(abo);
>
> +     amdgpu_amdkfd_remove_fence_on_pt_pd_bos(abo);
> +     abo->vm_bo = NULL;
> +
>       if (bo->mem.mem_type != TTM_PL_VRAM || !bo->mem.mm_node ||
>           !(abo->flags & AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE))
>               return;
>
> -     dma_resv_lock(bo->base.resv, NULL);
> +     /* Only kfd bo wipe vram on release. The resv is &_resv. */
> +     dma_resv_lock(&bo->base._resv, NULL);
>
> -     r = amdgpu_fill_buffer(abo, AMDGPU_POISON, bo->base.resv, &fence);
> +     r = amdgpu_fill_buffer(abo, AMDGPU_POISON, &bo->base._resv, &fence);
>       if (!WARN_ON(r)) {
>               amdgpu_bo_fence(abo, fence, false);
>               dma_fence_put(fence);
>       }
>
> -     dma_resv_unlock(bo->base.resv);
> +     dma_resv_unlock(&bo->base._resv);
>   }
>
>   /**
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index cc56eaba1911..2b96447e30e5 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -945,7 +945,6 @@ static int amdgpu_vm_alloc_pts(struct amdgpu_device *adev,
>   static void amdgpu_vm_free_table(struct amdgpu_vm_pt *entry)
>   {
>       if (entry->base.bo) {
> -             entry->base.bo->vm_bo = NULL;
>               list_del(&entry->base.vm_status);
>               amdgpu_bo_unref(&entry->base.bo->shadow);
>               amdgpu_bo_unref(&entry->base.bo);
> @@ -3074,6 +3073,7 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
>       struct amdgpu_bo_va_mapping *mapping, *tmp;
>       bool prt_fini_needed = !!adev->gmc.gmc_funcs->set_prt;
>       struct amdgpu_bo *root;
> +     struct ttm_bo_global *glob = &ttm_bo_glob;
>       int i;
>
>       amdgpu_amdkfd_gpuvm_destroy_cb(adev, vm);
> @@ -3105,6 +3105,9 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
>       }
>
>       amdgpu_vm_free_pts(adev, vm, NULL);
> +     spin_lock(&glob->lru_lock);
> +     root->vm_bo = NULL;
> +     spin_unlock(&glob->lru_lock);
>       amdgpu_bo_unreserve(root);
>       amdgpu_bo_unref(&root);
>       WARN_ON(vm->root.base.bo);
> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
> index 1494aebb8128..706cd60eb9e0 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
> @@ -429,8 +429,8 @@ static int ttm_bo_individualize_resv(struct ttm_buffer_object *bo)
>       BUG_ON(!dma_resv_trylock(&bo->base._resv));
>
>       r = dma_resv_copy_fences(&bo->base._resv, bo->base.resv);
> -     if (r)
> -             dma_resv_unlock(&bo->base._resv);
> +
> +     dma_resv_unlock(&bo->base._resv);
>
>       return r;
>   }
> @@ -455,23 +455,19 @@ static void ttm_bo_flush_all_fences(struct ttm_buffer_object *bo)
>       }
>   }
>
> -static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)
> +static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo, bool enqueue)
>   {
>       struct ttm_bo_device *bdev = bo->bdev;
>       int ret;
>
> -     ret = ttm_bo_individualize_resv(bo);
> -     if (ret) {
> -             /* Last resort, if we fail to allocate memory for the
> -              * fences block for the BO to become idle
> -              */
> -             dma_resv_wait_timeout_rcu(bo->base.resv, true, false,
> -                                                 30 * HZ);
> -             spin_lock(&ttm_bo_glob.lru_lock);
> -             goto error;
> -     }
> -
>       spin_lock(&ttm_bo_glob.lru_lock);
> +
> +     if (enqueue)
> +             goto queue;
> +
> +     if (bo->base.resv != &bo->base._resv)
> +             BUG_ON(!dma_resv_trylock(&bo->base._resv));
> +
>       ret = dma_resv_trylock(bo->base.resv) ? 0 : -EBUSY;
>       if (!ret) {
>               if (dma_resv_test_signaled_rcu(&bo->base._resv, true)) {
> @@ -504,7 +500,7 @@ static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)
>               dma_resv_unlock(&bo->base._resv);
>       }
>
> -error:
> +queue:
>       kref_get(&bo->list_kref);
>       list_add_tail(&bo->ddestroy, &bdev->ddestroy);
>       spin_unlock(&ttm_bo_glob.lru_lock);
> @@ -655,6 +651,16 @@ static void ttm_bo_release(struct kref *kref)
>           container_of(kref, struct ttm_buffer_object, kref);
>       struct ttm_bo_device *bdev = bo->bdev;
>       struct ttm_mem_type_manager *man = &bdev->man[bo->mem.mem_type];
> +     int ret;
> +
> +     ret = ttm_bo_individualize_resv(bo);
> +     if (ret) {
> +             /* Last resort, if we fail to allocate memory for the
> +              * fences block for the BO to become idle
> +              */
> +             dma_resv_wait_timeout_rcu(bo->base.resv, true, false,
> +                             30 * HZ);
> +     }
>
>       if (bo->bdev->driver->release_notify)
>               bo->bdev->driver->release_notify(bo);
> @@ -663,7 +669,7 @@ static void ttm_bo_release(struct kref *kref)
>       ttm_mem_io_lock(man, false);
>       ttm_mem_io_free_vm(bo);
>       ttm_mem_io_unlock(man);
> -     ttm_bo_cleanup_refs_or_queue(bo);
> +     ttm_bo_cleanup_refs_or_queue(bo, !!ret);
>       kref_put(&bo->list_kref, ttm_bo_release_list);
>   }
>

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^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: 回复: [RFC PATCH v2] drm/amdgpu: Remove kfd eviction fence before release bo
  2020-02-07 13:50   ` 回复: " Pan, Xinhui
@ 2020-02-07 13:52     ` Christian König
  0 siblings, 0 replies; 4+ messages in thread
From: Christian König @ 2020-02-07 13:52 UTC (permalink / raw)
  To: Pan, Xinhui, amd-gfx; +Cc: Deucher, Alexander, Kuehling, Felix

Am 07.02.20 um 14:50 schrieb Pan, Xinhui:
> [AMD Official Use Only - Internal Distribution Only]
>
> ________________________________________
> 发件人: Koenig, Christian <Christian.Koenig@amd.com>
> 发送时间: 2020年2月7日 21:46
> 收件人: Pan, Xinhui; amd-gfx@lists.freedesktop.org
> 抄送: Kuehling, Felix; Deucher, Alexander
> 主题: Re: [RFC PATCH v2] drm/amdgpu: Remove kfd eviction fence before release bo
>
> Am 07.02.20 um 14:42 schrieb Pan, Xinhui:
>> No need to trigger eviction as the memory mapping will not be used anymore.
>>
>> All pt/pd bos share same resv, hence the same shared eviction fence. Everytime page table is freed, the fence will be signled and that cuases kfd unexcepted evictions.
>>
>> Signed-off-by: xinhui pab <xinhui.pan@example.com>
>> ---
>>    drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h    |  1 +
>>    .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c  | 78 ++++++++++++++++++-
>>    drivers/gpu/drm/amd/amdgpu/amdgpu_object.c    | 10 ++-
>>    drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c        |  5 +-
>>    drivers/gpu/drm/ttm/ttm_bo.c                  | 38 +++++----
>>    5 files changed, 111 insertions(+), 21 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
>> index 47b0f2957d1f..265b1ed7264c 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
>> @@ -96,6 +96,7 @@ struct amdgpu_amdkfd_fence *amdgpu_amdkfd_fence_create(u64 context,
>>                                                       struct mm_struct *mm);
>>    bool amdkfd_fence_check_mm(struct dma_fence *f, struct mm_struct *mm);
>>    struct amdgpu_amdkfd_fence *to_amdgpu_amdkfd_fence(struct dma_fence *f);
>> +int amdgpu_amdkfd_remove_fence_on_pt_pd_bos(struct amdgpu_bo *bo);
>>
>>    struct amdkfd_process_info {
>>        /* List head of all VMs that belong to a KFD process */
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
>> index ef721cb65868..11315095c29b 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
>> @@ -223,7 +223,7 @@ void amdgpu_amdkfd_unreserve_memory_limit(struct amdgpu_bo *bo)
>>    static int amdgpu_amdkfd_remove_eviction_fence(struct amdgpu_bo *bo,
>>                                        struct amdgpu_amdkfd_fence *ef)
>>    {
>> -     struct dma_resv *resv = bo->tbo.base.resv;
>> +     struct dma_resv *resv = &bo->tbo.base._resv;
> That won't work either and probably break a bunch of other cases.
>
> [xh] kfd bos which are allocated explicitly use _resv AFAIK.
> only pt/pd bos share the root._resv

No that is not correct. Imports potentially don't use _resv here.

Anyway please see the patchset I've pointed out in one of my last mails. 
With that we can assign bo->tbo.base.resv to bo->tbo._base for deleted BOs.

Christian.

>
> Christian.
>
>>        struct dma_resv_list *old, *new;
>>        unsigned int i, j, k;
>>
>> @@ -276,6 +276,78 @@ static int amdgpu_amdkfd_remove_eviction_fence(struct amdgpu_bo *bo,
>>        return 0;
>>    }
>>
>> +int amdgpu_amdkfd_remove_fence_on_pt_pd_bos(struct amdgpu_bo *bo)
>> +{
>> +     struct amdgpu_vm_bo_base        *vm_bo = bo->vm_bo;
>> +     struct amdgpu_vm *vm;
>> +     struct amdkfd_process_info *info;
>> +     struct amdgpu_amdkfd_fence *ef;
>> +     struct amdgpu_bo *parent;
>> +     int locked;
>> +     int ret;
>> +     struct ttm_bo_global *glob = &ttm_bo_glob;
>> +
>> +     if (vm_bo == NULL)
>> +             return 0;
>> +
>> +     /* Page table bo has a reference of the parent bo.
>> +      * BO itself can't guarntee the vm it points to is alive.
>> +      * for example, VM is going to free page tables, and the pt/pd bo might be
>> +      * freed by a workqueue. In that case, the vm might be freed already,
>> +      * leaving the bo->vm_bo points to vm.root.
>> +      *
>> +      * so to avoid that, when kfd free its vms,
>> +      * 1) set vm->process_info to NULL if this is the last vm.
>> +      * 2) set root_bo->vm_bo to NULL.
>> +      *
>> +      * but there are still races, just like
>> +      * cpu 1                cpu 2
>> +      *                      !vm_bo
>> +      * ->info = NULL
>> +      * free(info)
>> +      * ->vm_bo = NULL
>> +      * free (vm)
>> +      *                      info = vm->info //invalid vm
>> +      *
>> +      * So to avoid the race, use ttm_bo_glob lru_lock.
>> +      * generally speaking, adding a new lock is accceptable.
>> +      * But reusing this lock is simple.
>> +      */
>> +     parent = bo;
>> +     while (parent->parent)
>> +             parent = parent->parent;
>> +
>> +     spin_lock(&glob->lru_lock);
>> +     vm_bo = parent->vm_bo;
>> +     if (!vm_bo) {
>> +             spin_unlock(&glob->lru_lock);
>> +             return 0;
>> +     }
>> +
>> +     vm = vm_bo->vm;
>> +     if (!vm) {
>> +             spin_unlock(&glob->lru_lock);
>> +             return 0;
>> +     }
>> +
>> +     info = vm->process_info;
>> +     if (!info || !info->eviction_fence) {
>> +             spin_unlock(&glob->lru_lock);
>> +             return 0;
>> +     }
>> +
>> +     ef = container_of(dma_fence_get(&info->eviction_fence->base),
>> +                     struct amdgpu_amdkfd_fence, base);
>> +     spin_unlock(&glob->lru_lock);
>> +
>> +     locked = dma_resv_trylock(&bo->tbo.base._resv);
>> +     ret = amdgpu_amdkfd_remove_eviction_fence(bo, ef);
>> +     dma_fence_put(&ef->base);
>> +     if (locked)
>> +             dma_resv_unlock(&bo->tbo.base._resv);
>> +     return ret;
>> +}
>> +
>>    static int amdgpu_amdkfd_bo_validate(struct amdgpu_bo *bo, uint32_t domain,
>>                                     bool wait)
>>    {
>> @@ -1030,6 +1102,7 @@ void amdgpu_amdkfd_gpuvm_destroy_cb(struct amdgpu_device *adev,
>>    {
>>        struct amdkfd_process_info *process_info = vm->process_info;
>>        struct amdgpu_bo *pd = vm->root.base.bo;
>> +     struct ttm_bo_global *glob = &ttm_bo_glob;
>>
>>        if (!process_info)
>>                return;
>> @@ -1051,6 +1124,9 @@ void amdgpu_amdkfd_gpuvm_destroy_cb(struct amdgpu_device *adev,
>>                WARN_ON(!list_empty(&process_info->userptr_valid_list));
>>                WARN_ON(!list_empty(&process_info->userptr_inval_list));
>>
>> +             spin_lock(&glob->lru_lock);
>> +             vm->process_info = NULL;
>> +             spin_unlock(&glob->lru_lock);
>>                dma_fence_put(&process_info->eviction_fence->base);
>>                cancel_delayed_work_sync(&process_info->restore_userptr_work);
>>                put_pid(process_info->pid);
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>> index 6f60a581e3ba..6ad12298fa84 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
>> @@ -1307,19 +1307,23 @@ void amdgpu_bo_release_notify(struct ttm_buffer_object *bo)
>>        if (abo->kfd_bo)
>>                amdgpu_amdkfd_unreserve_memory_limit(abo);
>>
>> +     amdgpu_amdkfd_remove_fence_on_pt_pd_bos(abo);
>> +     abo->vm_bo = NULL;
>> +
>>        if (bo->mem.mem_type != TTM_PL_VRAM || !bo->mem.mm_node ||
>>            !(abo->flags & AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE))
>>                return;
>>
>> -     dma_resv_lock(bo->base.resv, NULL);
>> +     /* Only kfd bo wipe vram on release. The resv is &_resv. */
>> +     dma_resv_lock(&bo->base._resv, NULL);
>>
>> -     r = amdgpu_fill_buffer(abo, AMDGPU_POISON, bo->base.resv, &fence);
>> +     r = amdgpu_fill_buffer(abo, AMDGPU_POISON, &bo->base._resv, &fence);
>>        if (!WARN_ON(r)) {
>>                amdgpu_bo_fence(abo, fence, false);
>>                dma_fence_put(fence);
>>        }
>>
>> -     dma_resv_unlock(bo->base.resv);
>> +     dma_resv_unlock(&bo->base._resv);
>>    }
>>
>>    /**
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> index cc56eaba1911..2b96447e30e5 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> @@ -945,7 +945,6 @@ static int amdgpu_vm_alloc_pts(struct amdgpu_device *adev,
>>    static void amdgpu_vm_free_table(struct amdgpu_vm_pt *entry)
>>    {
>>        if (entry->base.bo) {
>> -             entry->base.bo->vm_bo = NULL;
>>                list_del(&entry->base.vm_status);
>>                amdgpu_bo_unref(&entry->base.bo->shadow);
>>                amdgpu_bo_unref(&entry->base.bo);
>> @@ -3074,6 +3073,7 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
>>        struct amdgpu_bo_va_mapping *mapping, *tmp;
>>        bool prt_fini_needed = !!adev->gmc.gmc_funcs->set_prt;
>>        struct amdgpu_bo *root;
>> +     struct ttm_bo_global *glob = &ttm_bo_glob;
>>        int i;
>>
>>        amdgpu_amdkfd_gpuvm_destroy_cb(adev, vm);
>> @@ -3105,6 +3105,9 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
>>        }
>>
>>        amdgpu_vm_free_pts(adev, vm, NULL);
>> +     spin_lock(&glob->lru_lock);
>> +     root->vm_bo = NULL;
>> +     spin_unlock(&glob->lru_lock);
>>        amdgpu_bo_unreserve(root);
>>        amdgpu_bo_unref(&root);
>>        WARN_ON(vm->root.base.bo);
>> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
>> index 1494aebb8128..706cd60eb9e0 100644
>> --- a/drivers/gpu/drm/ttm/ttm_bo.c
>> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
>> @@ -429,8 +429,8 @@ static int ttm_bo_individualize_resv(struct ttm_buffer_object *bo)
>>        BUG_ON(!dma_resv_trylock(&bo->base._resv));
>>
>>        r = dma_resv_copy_fences(&bo->base._resv, bo->base.resv);
>> -     if (r)
>> -             dma_resv_unlock(&bo->base._resv);
>> +
>> +     dma_resv_unlock(&bo->base._resv);
>>
>>        return r;
>>    }
>> @@ -455,23 +455,19 @@ static void ttm_bo_flush_all_fences(struct ttm_buffer_object *bo)
>>        }
>>    }
>>
>> -static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)
>> +static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo, bool enqueue)
>>    {
>>        struct ttm_bo_device *bdev = bo->bdev;
>>        int ret;
>>
>> -     ret = ttm_bo_individualize_resv(bo);
>> -     if (ret) {
>> -             /* Last resort, if we fail to allocate memory for the
>> -              * fences block for the BO to become idle
>> -              */
>> -             dma_resv_wait_timeout_rcu(bo->base.resv, true, false,
>> -                                                 30 * HZ);
>> -             spin_lock(&ttm_bo_glob.lru_lock);
>> -             goto error;
>> -     }
>> -
>>        spin_lock(&ttm_bo_glob.lru_lock);
>> +
>> +     if (enqueue)
>> +             goto queue;
>> +
>> +     if (bo->base.resv != &bo->base._resv)
>> +             BUG_ON(!dma_resv_trylock(&bo->base._resv));
>> +
>>        ret = dma_resv_trylock(bo->base.resv) ? 0 : -EBUSY;
>>        if (!ret) {
>>                if (dma_resv_test_signaled_rcu(&bo->base._resv, true)) {
>> @@ -504,7 +500,7 @@ static void ttm_bo_cleanup_refs_or_queue(struct ttm_buffer_object *bo)
>>                dma_resv_unlock(&bo->base._resv);
>>        }
>>
>> -error:
>> +queue:
>>        kref_get(&bo->list_kref);
>>        list_add_tail(&bo->ddestroy, &bdev->ddestroy);
>>        spin_unlock(&ttm_bo_glob.lru_lock);
>> @@ -655,6 +651,16 @@ static void ttm_bo_release(struct kref *kref)
>>            container_of(kref, struct ttm_buffer_object, kref);
>>        struct ttm_bo_device *bdev = bo->bdev;
>>        struct ttm_mem_type_manager *man = &bdev->man[bo->mem.mem_type];
>> +     int ret;
>> +
>> +     ret = ttm_bo_individualize_resv(bo);
>> +     if (ret) {
>> +             /* Last resort, if we fail to allocate memory for the
>> +              * fences block for the BO to become idle
>> +              */
>> +             dma_resv_wait_timeout_rcu(bo->base.resv, true, false,
>> +                             30 * HZ);
>> +     }
>>
>>        if (bo->bdev->driver->release_notify)
>>                bo->bdev->driver->release_notify(bo);
>> @@ -663,7 +669,7 @@ static void ttm_bo_release(struct kref *kref)
>>        ttm_mem_io_lock(man, false);
>>        ttm_mem_io_free_vm(bo);
>>        ttm_mem_io_unlock(man);
>> -     ttm_bo_cleanup_refs_or_queue(bo);
>> +     ttm_bo_cleanup_refs_or_queue(bo, !!ret);
>>        kref_put(&bo->list_kref, ttm_bo_release_list);
>>    }
>>

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^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2020-02-07 13:52 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-02-07 13:42 [RFC PATCH v2] drm/amdgpu: Remove kfd eviction fence before release bo Pan, Xinhui
2020-02-07 13:46 ` Christian König
2020-02-07 13:50   ` 回复: " Pan, Xinhui
2020-02-07 13:52     ` Christian König

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