[PATCH v4 1/2] drm/amdgpu: Fix amdgpu_vm_pt_free warning

[PATCH v4 1/2] drm/amdgpu: Fix amdgpu_vm_pt_free warning

[Philip Yang]

Free page table BO from vm resv unlocked context generate below
warnings.

Add a pt_free_work in vm to free page table BO from vm->pt_freed list.
pass vm resv unlock status from page table update caller, and add vm_bo
entry to vm->pt_freed list and schedule the pt_free_work if calling with
vm resv unlocked.

WARNING: CPU: 12 PID: 3238 at
drivers/gpu/drm/ttm/ttm_bo.c:106 ttm_bo_set_bulk_move+0xa1/0xc0
Call Trace:
 amdgpu_vm_pt_free+0x42/0xd0 [amdgpu]
 amdgpu_vm_pt_free_dfs+0xb3/0xf0 [amdgpu]
 amdgpu_vm_ptes_update+0x52d/0x850 [amdgpu]
 amdgpu_vm_update_range+0x2a6/0x640 [amdgpu]
 svm_range_unmap_from_gpus+0x110/0x300 [amdgpu]
 svm_range_cpu_invalidate_pagetables+0x535/0x600 [amdgpu]
 __mmu_notifier_invalidate_range_start+0x1cd/0x230
 unmap_vmas+0x9d/0x140
 unmap_region+0xa8/0x110

Signed-off-by: Philip Yang <Philip.Yang@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c    |  4 ++
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h    |  6 +++
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c | 47 ++++++++++++++++++++---
 3 files changed, 51 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 59cac347baa3..27e6155053b6 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2022,6 +2022,9 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 	spin_lock_init(&vm->invalidated_lock);
 	INIT_LIST_HEAD(&vm->freed);
 	INIT_LIST_HEAD(&vm->done);
+	INIT_LIST_HEAD(&vm->pt_freed);
+	INIT_WORK(&vm->pt_free_work, amdgpu_vm_pt_free_work);
+	spin_lock_init(&vm->pt_free_lock);
 
 	/* create scheduler entities for page table updates */
 	r = drm_sched_entity_init(&vm->immediate, DRM_SCHED_PRIORITY_NORMAL,
@@ -2244,6 +2247,7 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 		amdgpu_vm_free_mapping(adev, vm, mapping, NULL);
 	}
 
+	cancel_work_sync(&vm->pt_free_work);
 	amdgpu_vm_pt_free_root(adev, vm);
 	amdgpu_bo_unreserve(root);
 	amdgpu_bo_unref(&root);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
index 9ecb7f663e19..b77fe838c327 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
@@ -276,6 +276,11 @@ struct amdgpu_vm {
 	/* BOs which are invalidated, has been updated in the PTs */
 	struct list_head        done;
 
+	/* PT BOs scheduled to free and fill with zero if vm_resv is not hold */
+	struct list_head	pt_freed;
+	struct work_struct	pt_free_work;
+	spinlock_t		pt_free_lock;
+
 	/* contains the page directory */
 	struct amdgpu_vm_bo_base     root;
 	struct dma_fence	*last_update;
@@ -471,6 +476,7 @@ int amdgpu_vm_pde_update(struct amdgpu_vm_update_params *params,
 int amdgpu_vm_ptes_update(struct amdgpu_vm_update_params *params,
 			  uint64_t start, uint64_t end,
 			  uint64_t dst, uint64_t flags);
+void amdgpu_vm_pt_free_work(struct work_struct *work);
 
 #if defined(CONFIG_DEBUG_FS)
 void amdgpu_debugfs_vm_bo_info(struct amdgpu_vm *vm, struct seq_file *m);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
index 88de9f0d4728..c6f91731ecfb 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
@@ -624,12 +624,22 @@ static int amdgpu_vm_pt_alloc(struct amdgpu_device *adev,
  *
  * @entry: PDE to free
  */
-static void amdgpu_vm_pt_free(struct amdgpu_vm_bo_base *entry)
+static void amdgpu_vm_pt_free(struct amdgpu_vm_bo_base *entry, bool unlocked)
 {
 	struct amdgpu_bo *shadow;
 
 	if (!entry->bo)
 		return;
+
+	if (unlocked) {
+		spin_lock(&entry->vm->pt_free_lock);
+		list_move(&entry->vm_status, &entry->vm->pt_freed);
+		spin_unlock(&entry->vm->pt_free_lock);
+
+		schedule_work(&entry->vm->pt_free_work);
+		return;
+	}
+
 	shadow = amdgpu_bo_shadowed(entry->bo);
 	if (shadow) {
 		ttm_bo_set_bulk_move(&shadow->tbo, NULL);
@@ -641,6 +651,29 @@ static void amdgpu_vm_pt_free(struct amdgpu_vm_bo_base *entry)
 	amdgpu_bo_unref(&entry->bo);
 }
 
+void amdgpu_vm_pt_free_work(struct work_struct *work)
+{
+	struct amdgpu_vm_bo_base *entry, *next;
+	struct amdgpu_vm *vm;
+	struct amdgpu_bo *root;
+	LIST_HEAD(pt_freed);
+
+	vm = container_of(work, struct amdgpu_vm, pt_free_work);
+
+	spin_lock(&vm->pt_free_lock);
+	list_splice_init(&vm->pt_freed, &pt_freed);
+	spin_unlock(&vm->pt_free_lock);
+
+	root = amdgpu_bo_ref(vm->root.bo);
+	amdgpu_bo_reserve(root, true);
+
+	list_for_each_entry_safe(entry, next, &pt_freed, vm_status)
+		amdgpu_vm_pt_free(entry, false);
+
+	amdgpu_bo_unreserve(root);
+	amdgpu_bo_unref(&root);
+}
+
 /**
  * amdgpu_vm_pt_free_dfs - free PD/PT levels
  *
@@ -652,16 +685,17 @@ static void amdgpu_vm_pt_free(struct amdgpu_vm_bo_base *entry)
  */
 static void amdgpu_vm_pt_free_dfs(struct amdgpu_device *adev,
 				  struct amdgpu_vm *vm,
-				  struct amdgpu_vm_pt_cursor *start)
+				  struct amdgpu_vm_pt_cursor *start,
+				  bool unlocked)
 {
 	struct amdgpu_vm_pt_cursor cursor;
 	struct amdgpu_vm_bo_base *entry;
 
 	for_each_amdgpu_vm_pt_dfs_safe(adev, vm, start, cursor, entry)
-		amdgpu_vm_pt_free(entry);
+		amdgpu_vm_pt_free(entry, unlocked);
 
 	if (start)
-		amdgpu_vm_pt_free(start->entry);
+		amdgpu_vm_pt_free(start->entry, unlocked);
 }
 
 /**
@@ -673,7 +707,7 @@ static void amdgpu_vm_pt_free_dfs(struct amdgpu_device *adev,
  */
 void amdgpu_vm_pt_free_root(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 {
-	amdgpu_vm_pt_free_dfs(adev, vm, NULL);
+	amdgpu_vm_pt_free_dfs(adev, vm, NULL, false);
 }
 
 /**
@@ -966,7 +1000,8 @@ int amdgpu_vm_ptes_update(struct amdgpu_vm_update_params *params,
 				if (cursor.entry->bo) {
 					params->table_freed = true;
 					amdgpu_vm_pt_free_dfs(adev, params->vm,
-							      &cursor);
+							      &cursor,
+							      params->unlocked);
 				}
 				amdgpu_vm_pt_next(adev, &cursor);
 			}
-- 
2.35.1

[PATCH v4 2/2] drm/amdgpu: SDMA update use unlocked iterator

[Philip Yang]

SDMA update page table may be called from unlocked context, this
generate below warning. Use unlocked iterator to handle this case.

WARNING: CPU: 0 PID: 1475 at
drivers/dma-buf/dma-resv.c:483 dma_resv_iter_next
Call Trace:
 dma_resv_iter_first+0x43/0xa0
 amdgpu_vm_sdma_update+0x69/0x2d0 [amdgpu]
 amdgpu_vm_ptes_update+0x29c/0x870 [amdgpu]
 amdgpu_vm_update_range+0x2f6/0x6c0 [amdgpu]
 svm_range_unmap_from_gpus+0x115/0x300 [amdgpu]
 svm_range_cpu_invalidate_pagetables+0x510/0x5e0 [amdgpu]
 __mmu_notifier_invalidate_range_start+0x1d3/0x230
 unmap_vmas+0x140/0x150
 unmap_region+0xa8/0x110

Signed-off-by: Philip Yang <Philip.Yang@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
index 1fd3cbca20a2..718db7d98e5a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
@@ -211,12 +211,15 @@ static int amdgpu_vm_sdma_update(struct amdgpu_vm_update_params *p,
 	int r;
 
 	/* Wait for PD/PT moves to be completed */
-	dma_resv_for_each_fence(&cursor, bo->tbo.base.resv,
-				DMA_RESV_USAGE_KERNEL, fence) {
+	dma_resv_iter_begin(&cursor, bo->tbo.base.resv, DMA_RESV_USAGE_KERNEL);
+	dma_resv_for_each_fence_unlocked(&cursor, fence) {
 		r = amdgpu_sync_fence(&p->job->sync, fence);
-		if (r)
+		if (r) {
+			dma_resv_iter_end(&cursor);
 			return r;
+		}
 	}
+	dma_resv_iter_end(&cursor);
 
 	do {
 		ndw = p->num_dw_left;
-- 
2.35.1

Re: [PATCH v4 1/2] drm/amdgpu: Fix amdgpu_vm_pt_free warning

[Christian König]

Am 13.09.22 um 22:05 schrieb Philip Yang:
> Free page table BO from vm resv unlocked context generate below
> warnings.
>
> Add a pt_free_work in vm to free page table BO from vm->pt_freed list.
> pass vm resv unlock status from page table update caller, and add vm_bo
> entry to vm->pt_freed list and schedule the pt_free_work if calling with
> vm resv unlocked.
>
> WARNING: CPU: 12 PID: 3238 at
> drivers/gpu/drm/ttm/ttm_bo.c:106 ttm_bo_set_bulk_move+0xa1/0xc0
> Call Trace:
>   amdgpu_vm_pt_free+0x42/0xd0 [amdgpu]
>   amdgpu_vm_pt_free_dfs+0xb3/0xf0 [amdgpu]
>   amdgpu_vm_ptes_update+0x52d/0x850 [amdgpu]
>   amdgpu_vm_update_range+0x2a6/0x640 [amdgpu]
>   svm_range_unmap_from_gpus+0x110/0x300 [amdgpu]
>   svm_range_cpu_invalidate_pagetables+0x535/0x600 [amdgpu]
>   __mmu_notifier_invalidate_range_start+0x1cd/0x230
>   unmap_vmas+0x9d/0x140
>   unmap_region+0xa8/0x110
>
> Signed-off-by: Philip Yang <Philip.Yang@amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c    |  4 ++
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h    |  6 +++
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c | 47 ++++++++++++++++++++---
>   3 files changed, 51 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index 59cac347baa3..27e6155053b6 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -2022,6 +2022,9 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm)
>   	spin_lock_init(&vm->invalidated_lock);
>   	INIT_LIST_HEAD(&vm->freed);
>   	INIT_LIST_HEAD(&vm->done);
> +	INIT_LIST_HEAD(&vm->pt_freed);
> +	INIT_WORK(&vm->pt_free_work, amdgpu_vm_pt_free_work);
> +	spin_lock_init(&vm->pt_free_lock);
>   
>   	/* create scheduler entities for page table updates */
>   	r = drm_sched_entity_init(&vm->immediate, DRM_SCHED_PRIORITY_NORMAL,
> @@ -2244,6 +2247,7 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
>   		amdgpu_vm_free_mapping(adev, vm, mapping, NULL);
>   	}
>   
> +	cancel_work_sync(&vm->pt_free_work);

We should probably not cancel the work here, but rather just wait for it 
to finish.

>   	amdgpu_vm_pt_free_root(adev, vm);
>   	amdgpu_bo_unreserve(root);
>   	amdgpu_bo_unref(&root);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> index 9ecb7f663e19..b77fe838c327 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
> @@ -276,6 +276,11 @@ struct amdgpu_vm {
>   	/* BOs which are invalidated, has been updated in the PTs */
>   	struct list_head        done;
>   
> +	/* PT BOs scheduled to free and fill with zero if vm_resv is not hold */
> +	struct list_head	pt_freed;
> +	struct work_struct	pt_free_work;
> +	spinlock_t		pt_free_lock;
> +
>   	/* contains the page directory */
>   	struct amdgpu_vm_bo_base     root;
>   	struct dma_fence	*last_update;
> @@ -471,6 +476,7 @@ int amdgpu_vm_pde_update(struct amdgpu_vm_update_params *params,
>   int amdgpu_vm_ptes_update(struct amdgpu_vm_update_params *params,
>   			  uint64_t start, uint64_t end,
>   			  uint64_t dst, uint64_t flags);
> +void amdgpu_vm_pt_free_work(struct work_struct *work);
>   
>   #if defined(CONFIG_DEBUG_FS)
>   void amdgpu_debugfs_vm_bo_info(struct amdgpu_vm *vm, struct seq_file *m);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
> index 88de9f0d4728..c6f91731ecfb 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
> @@ -624,12 +624,22 @@ static int amdgpu_vm_pt_alloc(struct amdgpu_device *adev,
>    *
>    * @entry: PDE to free
>    */
> -static void amdgpu_vm_pt_free(struct amdgpu_vm_bo_base *entry)
> +static void amdgpu_vm_pt_free(struct amdgpu_vm_bo_base *entry, bool unlocked)
>   {
>   	struct amdgpu_bo *shadow;
>   
>   	if (!entry->bo)
>   		return;
> +
> +	if (unlocked) {
> +		spin_lock(&entry->vm->pt_free_lock);
> +		list_move(&entry->vm_status, &entry->vm->pt_freed);
> +		spin_unlock(&entry->vm->pt_free_lock);
> +
> +		schedule_work(&entry->vm->pt_free_work);
> +		return;
> +	}
> +

I strongly prefer to handle this in amdgpu_vm_pt_free_dfs() or even the 
caller of this instead and keep this here the low level free function.

>   	shadow = amdgpu_bo_shadowed(entry->bo);
>   	if (shadow) {
>   		ttm_bo_set_bulk_move(&shadow->tbo, NULL);
> @@ -641,6 +651,29 @@ static void amdgpu_vm_pt_free(struct amdgpu_vm_bo_base *entry)
>   	amdgpu_bo_unref(&entry->bo);
>   }
>   
> +void amdgpu_vm_pt_free_work(struct work_struct *work)

I think we could make this one here static if we introduce a 
amdgpu_vm_pt_init()/amdgpu_vm_pt_fini() function. But not a must have.

Christian.

> +{
> +	struct amdgpu_vm_bo_base *entry, *next;
> +	struct amdgpu_vm *vm;
> +	struct amdgpu_bo *root;
> +	LIST_HEAD(pt_freed);
> +
> +	vm = container_of(work, struct amdgpu_vm, pt_free_work);
> +
> +	spin_lock(&vm->pt_free_lock);
> +	list_splice_init(&vm->pt_freed, &pt_freed);
> +	spin_unlock(&vm->pt_free_lock);
> +
> +	root = amdgpu_bo_ref(vm->root.bo);
> +	amdgpu_bo_reserve(root, true);
> +
> +	list_for_each_entry_safe(entry, next, &pt_freed, vm_status)
> +		amdgpu_vm_pt_free(entry, false);
> +
> +	amdgpu_bo_unreserve(root);
> +	amdgpu_bo_unref(&root);
> +}
> +
>   /**
>    * amdgpu_vm_pt_free_dfs - free PD/PT levels
>    *
> @@ -652,16 +685,17 @@ static void amdgpu_vm_pt_free(struct amdgpu_vm_bo_base *entry)
>    */
>   static void amdgpu_vm_pt_free_dfs(struct amdgpu_device *adev,
>   				  struct amdgpu_vm *vm,
> -				  struct amdgpu_vm_pt_cursor *start)
> +				  struct amdgpu_vm_pt_cursor *start,
> +				  bool unlocked)
>   {
>   	struct amdgpu_vm_pt_cursor cursor;
>   	struct amdgpu_vm_bo_base *entry;
>   
>   	for_each_amdgpu_vm_pt_dfs_safe(adev, vm, start, cursor, entry)
> -		amdgpu_vm_pt_free(entry);
> +		amdgpu_vm_pt_free(entry, unlocked);
>   
>   	if (start)
> -		amdgpu_vm_pt_free(start->entry);
> +		amdgpu_vm_pt_free(start->entry, unlocked);
>   }
>   
>   /**
> @@ -673,7 +707,7 @@ static void amdgpu_vm_pt_free_dfs(struct amdgpu_device *adev,
>    */
>   void amdgpu_vm_pt_free_root(struct amdgpu_device *adev, struct amdgpu_vm *vm)
>   {
> -	amdgpu_vm_pt_free_dfs(adev, vm, NULL);
> +	amdgpu_vm_pt_free_dfs(adev, vm, NULL, false);
>   }
>   
>   /**
> @@ -966,7 +1000,8 @@ int amdgpu_vm_ptes_update(struct amdgpu_vm_update_params *params,
>   				if (cursor.entry->bo) {
>   					params->table_freed = true;
>   					amdgpu_vm_pt_free_dfs(adev, params->vm,
> -							      &cursor);
> +							      &cursor,
> +							      params->unlocked);
>   				}
>   				amdgpu_vm_pt_next(adev, &cursor);
>   			}

Re: [PATCH v4 2/2] drm/amdgpu: SDMA update use unlocked iterator

[Christian König]

Am 13.09.22 um 22:05 schrieb Philip Yang:
> SDMA update page table may be called from unlocked context, this
> generate below warning. Use unlocked iterator to handle this case.
>
> WARNING: CPU: 0 PID: 1475 at
> drivers/dma-buf/dma-resv.c:483 dma_resv_iter_next
> Call Trace:
>   dma_resv_iter_first+0x43/0xa0
>   amdgpu_vm_sdma_update+0x69/0x2d0 [amdgpu]
>   amdgpu_vm_ptes_update+0x29c/0x870 [amdgpu]
>   amdgpu_vm_update_range+0x2f6/0x6c0 [amdgpu]
>   svm_range_unmap_from_gpus+0x115/0x300 [amdgpu]
>   svm_range_cpu_invalidate_pagetables+0x510/0x5e0 [amdgpu]
>   __mmu_notifier_invalidate_range_start+0x1d3/0x230
>   unmap_vmas+0x140/0x150
>   unmap_region+0xa8/0x110
>
> Signed-off-by: Philip Yang <Philip.Yang@amd.com>

Reviewed-by: Christian König <christian.koenig@amd.com>

> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c | 9 ++++++---
>   1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
> index 1fd3cbca20a2..718db7d98e5a 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
> @@ -211,12 +211,15 @@ static int amdgpu_vm_sdma_update(struct amdgpu_vm_update_params *p,
>   	int r;
>   
>   	/* Wait for PD/PT moves to be completed */
> -	dma_resv_for_each_fence(&cursor, bo->tbo.base.resv,
> -				DMA_RESV_USAGE_KERNEL, fence) {
> +	dma_resv_iter_begin(&cursor, bo->tbo.base.resv, DMA_RESV_USAGE_KERNEL);
> +	dma_resv_for_each_fence_unlocked(&cursor, fence) {
>   		r = amdgpu_sync_fence(&p->job->sync, fence);
> -		if (r)
> +		if (r) {
> +			dma_resv_iter_end(&cursor);
>   			return r;
> +		}
>   	}
> +	dma_resv_iter_end(&cursor);
>   
>   	do {
>   		ndw = p->num_dw_left;

Re: [PATCH v4 1/2] drm/amdgpu: Fix amdgpu_vm_pt_free warning

[Philip Yang]

On 2022-09-14 05:10, Christian König wrote:
> Am 13.09.22 um 22:05 schrieb Philip Yang:
>> Free page table BO from vm resv unlocked context generate below
>> warnings.
>>
>> Add a pt_free_work in vm to free page table BO from vm->pt_freed list.
>> pass vm resv unlock status from page table update caller, and add vm_bo
>> entry to vm->pt_freed list and schedule the pt_free_work if calling with
>> vm resv unlocked.
>>
>> WARNING: CPU: 12 PID: 3238 at
>> drivers/gpu/drm/ttm/ttm_bo.c:106 ttm_bo_set_bulk_move+0xa1/0xc0
>> Call Trace:
>>   amdgpu_vm_pt_free+0x42/0xd0 [amdgpu]
>>   amdgpu_vm_pt_free_dfs+0xb3/0xf0 [amdgpu]
>>   amdgpu_vm_ptes_update+0x52d/0x850 [amdgpu]
>>   amdgpu_vm_update_range+0x2a6/0x640 [amdgpu]
>>   svm_range_unmap_from_gpus+0x110/0x300 [amdgpu]
>>   svm_range_cpu_invalidate_pagetables+0x535/0x600 [amdgpu]
>>   __mmu_notifier_invalidate_range_start+0x1cd/0x230
>>   unmap_vmas+0x9d/0x140
>>   unmap_region+0xa8/0x110
>>
>> Signed-off-by: Philip Yang <Philip.Yang@amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c    |  4 ++
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h    |  6 +++
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c | 47 ++++++++++++++++++++---
>>   3 files changed, 51 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> index 59cac347baa3..27e6155053b6 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> @@ -2022,6 +2022,9 @@ int amdgpu_vm_init(struct amdgpu_device *adev, 
>> struct amdgpu_vm *vm)
>>       spin_lock_init(&vm->invalidated_lock);
>>       INIT_LIST_HEAD(&vm->freed);
>>       INIT_LIST_HEAD(&vm->done);
>> +    INIT_LIST_HEAD(&vm->pt_freed);
>> +    INIT_WORK(&vm->pt_free_work, amdgpu_vm_pt_free_work);
>> +    spin_lock_init(&vm->pt_free_lock);
>>         /* create scheduler entities for page table updates */
>>       r = drm_sched_entity_init(&vm->immediate, 
>> DRM_SCHED_PRIORITY_NORMAL,
>> @@ -2244,6 +2247,7 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, 
>> struct amdgpu_vm *vm)
>>           amdgpu_vm_free_mapping(adev, vm, mapping, NULL);
>>       }
>>   +    cancel_work_sync(&vm->pt_free_work);
>
> We should probably not cancel the work here, but rather just wait for 
> it to finish.
Good point, will change to flush_work, and move it outside 
amdgpu_bo_reserve(root), as amdgpu_vm_pt_free_work takes 
amdgpu_bo_reserve(root), this will cause deadlock.
>
>>       amdgpu_vm_pt_free_root(adev, vm);
>>       amdgpu_bo_unreserve(root);
>>       amdgpu_bo_unref(&root);
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
>> index 9ecb7f663e19..b77fe838c327 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
>> @@ -276,6 +276,11 @@ struct amdgpu_vm {
>>       /* BOs which are invalidated, has been updated in the PTs */
>>       struct list_head        done;
>>   +    /* PT BOs scheduled to free and fill with zero if vm_resv is 
>> not hold */
>> +    struct list_head    pt_freed;
>> +    struct work_struct    pt_free_work;
>> +    spinlock_t        pt_free_lock;
>> +
>>       /* contains the page directory */
>>       struct amdgpu_vm_bo_base     root;
>>       struct dma_fence    *last_update;
>> @@ -471,6 +476,7 @@ int amdgpu_vm_pde_update(struct 
>> amdgpu_vm_update_params *params,
>>   int amdgpu_vm_ptes_update(struct amdgpu_vm_update_params *params,
>>                 uint64_t start, uint64_t end,
>>                 uint64_t dst, uint64_t flags);
>> +void amdgpu_vm_pt_free_work(struct work_struct *work);
>>     #if defined(CONFIG_DEBUG_FS)
>>   void amdgpu_debugfs_vm_bo_info(struct amdgpu_vm *vm, struct 
>> seq_file *m);
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c 
>> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
>> index 88de9f0d4728..c6f91731ecfb 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_pt.c
>> @@ -624,12 +624,22 @@ static int amdgpu_vm_pt_alloc(struct 
>> amdgpu_device *adev,
>>    *
>>    * @entry: PDE to free
>>    */
>> -static void amdgpu_vm_pt_free(struct amdgpu_vm_bo_base *entry)
>> +static void amdgpu_vm_pt_free(struct amdgpu_vm_bo_base *entry, bool 
>> unlocked)
>>   {
>>       struct amdgpu_bo *shadow;
>>         if (!entry->bo)
>>           return;
>> +
>> +    if (unlocked) {
>> +        spin_lock(&entry->vm->pt_free_lock);
>> +        list_move(&entry->vm_status, &entry->vm->pt_freed);
>> +        spin_unlock(&entry->vm->pt_free_lock);
>> +
>> +        schedule_work(&entry->vm->pt_free_work);
>> +        return;
>> +    }
>> +
>
> I strongly prefer to handle this in amdgpu_vm_pt_free_dfs() or even 
> the caller of this instead and keep this here the low level free 
> function.

Agree. Will send out v5 patch.

Philip

>
>>       shadow = amdgpu_bo_shadowed(entry->bo);
>>       if (shadow) {
>>           ttm_bo_set_bulk_move(&shadow->tbo, NULL);
>> @@ -641,6 +651,29 @@ static void amdgpu_vm_pt_free(struct 
>> amdgpu_vm_bo_base *entry)
>>       amdgpu_bo_unref(&entry->bo);
>>   }
>>   +void amdgpu_vm_pt_free_work(struct work_struct *work)
>
> I think we could make this one here static if we introduce a 
> amdgpu_vm_pt_init()/amdgpu_vm_pt_fini() function. But not a must have.
>
> Christian.
>
>> +{
>> +    struct amdgpu_vm_bo_base *entry, *next;
>> +    struct amdgpu_vm *vm;
>> +    struct amdgpu_bo *root;
>> +    LIST_HEAD(pt_freed);
>> +
>> +    vm = container_of(work, struct amdgpu_vm, pt_free_work);
>> +
>> +    spin_lock(&vm->pt_free_lock);
>> +    list_splice_init(&vm->pt_freed, &pt_freed);
>> +    spin_unlock(&vm->pt_free_lock);
>> +
>> +    root = amdgpu_bo_ref(vm->root.bo);
>> +    amdgpu_bo_reserve(root, true);
>> +
>> +    list_for_each_entry_safe(entry, next, &pt_freed, vm_status)
>> +        amdgpu_vm_pt_free(entry, false);
>> +
>> +    amdgpu_bo_unreserve(root);
>> +    amdgpu_bo_unref(&root);
>> +}
>> +
>>   /**
>>    * amdgpu_vm_pt_free_dfs - free PD/PT levels
>>    *
>> @@ -652,16 +685,17 @@ static void amdgpu_vm_pt_free(struct 
>> amdgpu_vm_bo_base *entry)
>>    */
>>   static void amdgpu_vm_pt_free_dfs(struct amdgpu_device *adev,
>>                     struct amdgpu_vm *vm,
>> -                  struct amdgpu_vm_pt_cursor *start)
>> +                  struct amdgpu_vm_pt_cursor *start,
>> +                  bool unlocked)
>>   {
>>       struct amdgpu_vm_pt_cursor cursor;
>>       struct amdgpu_vm_bo_base *entry;
>>         for_each_amdgpu_vm_pt_dfs_safe(adev, vm, start, cursor, entry)
>> -        amdgpu_vm_pt_free(entry);
>> +        amdgpu_vm_pt_free(entry, unlocked);
>>         if (start)
>> -        amdgpu_vm_pt_free(start->entry);
>> +        amdgpu_vm_pt_free(start->entry, unlocked);
>>   }
>>     /**
>> @@ -673,7 +707,7 @@ static void amdgpu_vm_pt_free_dfs(struct 
>> amdgpu_device *adev,
>>    */
>>   void amdgpu_vm_pt_free_root(struct amdgpu_device *adev, struct 
>> amdgpu_vm *vm)
>>   {
>> -    amdgpu_vm_pt_free_dfs(adev, vm, NULL);
>> +    amdgpu_vm_pt_free_dfs(adev, vm, NULL, false);
>>   }
>>     /**
>> @@ -966,7 +1000,8 @@ int amdgpu_vm_ptes_update(struct 
>> amdgpu_vm_update_params *params,
>>                   if (cursor.entry->bo) {
>>                       params->table_freed = true;
>>                       amdgpu_vm_pt_free_dfs(adev, params->vm,
>> -                                  &cursor);
>> +                                  &cursor,
>> +                                  params->unlocked);
>>                   }
>>                   amdgpu_vm_pt_next(adev, &cursor);
>>               }
>