[PATCH v3 1/1] drm/amdgpu: fix amdgpu_vm_pt_free warning

Philip Yang Philip.Yang at amd.com
Tue Sep 13 13:19:26 UTC 2022


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

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 at 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



More information about the amd-gfx mailing list