drm/ttm: switch to per device LRU lock

Instead of having a global lock for potentially less contention.
Signed-off-by: Christian König <christian.koenig@amd.com>
Tested-by: Nirmoy Das <nirmoy.das@amd.com>
Reviewed-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/424010/

drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c

@@ -638,15 +638,15 @@ void amdgpu_vm_move_to_lru_tail(struct amdgpu_device *adev,
 	struct amdgpu_vm_bo_base *bo_base;
 
 	if (vm->bulk_moveable) {
-		spin_lock(&ttm_glob.lru_lock);
+		spin_lock(&adev->mman.bdev.lru_lock);
 		ttm_bo_bulk_move_lru_tail(&vm->lru_bulk_move);
-		spin_unlock(&ttm_glob.lru_lock);
+		spin_unlock(&adev->mman.bdev.lru_lock);
 		return;
 	}
 
 	memset(&vm->lru_bulk_move, 0, sizeof(vm->lru_bulk_move));
 
-	spin_lock(&ttm_glob.lru_lock);
+	spin_lock(&adev->mman.bdev.lru_lock);
 	list_for_each_entry(bo_base, &vm->idle, vm_status) {
 		struct amdgpu_bo *bo = bo_base->bo;
 
@@ -660,7 +660,7 @@ void amdgpu_vm_move_to_lru_tail(struct amdgpu_device *adev,
 						&bo->shadow->tbo.mem,
 						&vm->lru_bulk_move);
 	}
-	spin_unlock(&ttm_glob.lru_lock);
+	spin_unlock(&adev->mman.bdev.lru_lock);
 
 	vm->bulk_moveable = true;
 }

drivers/gpu/drm/qxl/qxl_release.c

@@ -426,16 +426,13 @@ void qxl_release_fence_buffer_objects(struct qxl_release *release)
 		       release->id | 0xf0000000, release->base.seqno);
 	trace_dma_fence_emit(&release->base);
 
-	spin_lock(&ttm_glob.lru_lock);
-
 	list_for_each_entry(entry, &release->bos, head) {
 		bo = entry->bo;
 
 		dma_resv_add_shared_fence(bo->base.resv, &release->base);
-		ttm_bo_move_to_lru_tail(bo, &bo->mem, NULL);
+		ttm_bo_move_to_lru_tail_unlocked(bo);
 		dma_resv_unlock(bo->base.resv);
 	}
-	spin_unlock(&ttm_glob.lru_lock);
 	ww_acquire_fini(&release->ticket);
 }
 

drivers/gpu/drm/ttm/ttm_bo.c

@@ -243,9 +243,9 @@ static int ttm_bo_individualize_resv(struct ttm_buffer_object *bo)
 		 * reference it any more. The only tricky case is the trylock on
 		 * the resv object while holding the lru_lock.
 		 */
-		spin_lock(&ttm_glob.lru_lock);
+		spin_lock(&bo->bdev->lru_lock);
 		bo->base.resv = &bo->base._resv;
-		spin_unlock(&ttm_glob.lru_lock);
+		spin_unlock(&bo->bdev->lru_lock);
 	}
 
 	return r;
@@ -304,7 +304,7 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo,
 
 		if (unlock_resv)
 			dma_resv_unlock(bo->base.resv);
-		spin_unlock(&ttm_glob.lru_lock);
+		spin_unlock(&bo->bdev->lru_lock);
 
 		lret = dma_resv_wait_timeout_rcu(resv, true, interruptible,
 						 30 * HZ);
@@ -314,7 +314,7 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo,
 		else if (lret == 0)
 			return -EBUSY;
 
-		spin_lock(&ttm_glob.lru_lock);
+		spin_lock(&bo->bdev->lru_lock);
 		if (unlock_resv && !dma_resv_trylock(bo->base.resv)) {
 			/*
 			 * We raced, and lost, someone else holds the reservation now,
@@ -324,7 +324,7 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo,
 			 * delayed destruction would succeed, so just return success
 			 * here.
 			 */
-			spin_unlock(&ttm_glob.lru_lock);
+			spin_unlock(&bo->bdev->lru_lock);
 			return 0;
 		}
 		ret = 0;
@@ -333,13 +333,13 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo,
 	if (ret || unlikely(list_empty(&bo->ddestroy))) {
 		if (unlock_resv)
 			dma_resv_unlock(bo->base.resv);
-		spin_unlock(&ttm_glob.lru_lock);
+		spin_unlock(&bo->bdev->lru_lock);
 		return ret;
 	}
 
 	ttm_bo_del_from_lru(bo);
 	list_del_init(&bo->ddestroy);
-	spin_unlock(&ttm_glob.lru_lock);
+	spin_unlock(&bo->bdev->lru_lock);
 	ttm_bo_cleanup_memtype_use(bo);
 
 	if (unlock_resv)
@@ -356,13 +356,12 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo,
  */
 bool ttm_bo_delayed_delete(struct ttm_device *bdev, bool remove_all)
 {
-	struct ttm_global *glob = &ttm_glob;
 	struct list_head removed;
 	bool empty;
 
 	INIT_LIST_HEAD(&removed);
 
-	spin_lock(&glob->lru_lock);
+	spin_lock(&bdev->lru_lock);
 	while (!list_empty(&bdev->ddestroy)) {
 		struct ttm_buffer_object *bo;
 
@@ -373,24 +372,24 @@ bool ttm_bo_delayed_delete(struct ttm_device *bdev, bool remove_all)
 			continue;
 
 		if (remove_all || bo->base.resv != &bo->base._resv) {
-			spin_unlock(&glob->lru_lock);
+			spin_unlock(&bdev->lru_lock);
 			dma_resv_lock(bo->base.resv, NULL);
 
-			spin_lock(&glob->lru_lock);
+			spin_lock(&bdev->lru_lock);
 			ttm_bo_cleanup_refs(bo, false, !remove_all, true);
 
 		} else if (dma_resv_trylock(bo->base.resv)) {
 			ttm_bo_cleanup_refs(bo, false, !remove_all, true);
 		} else {
-			spin_unlock(&glob->lru_lock);
+			spin_unlock(&bdev->lru_lock);
 		}
 
 		ttm_bo_put(bo);
-		spin_lock(&glob->lru_lock);
+		spin_lock(&bdev->lru_lock);
 	}
 	list_splice_tail(&removed, &bdev->ddestroy);
 	empty = list_empty(&bdev->ddestroy);
-	spin_unlock(&glob->lru_lock);
+	spin_unlock(&bdev->lru_lock);
 
 	return empty;
 }
@@ -425,7 +424,7 @@ static void ttm_bo_release(struct kref *kref)
 		ttm_bo_flush_all_fences(bo);
 		bo->deleted = true;
 
-		spin_lock(&ttm_glob.lru_lock);
+		spin_lock(&bo->bdev->lru_lock);
 
 		/*
 		 * Make pinned bos immediately available to
@@ -442,17 +441,17 @@ static void ttm_bo_release(struct kref *kref)
 
 		kref_init(&bo->kref);
 		list_add_tail(&bo->ddestroy, &bdev->ddestroy);
-		spin_unlock(&ttm_glob.lru_lock);
+		spin_unlock(&bo->bdev->lru_lock);
 
 		schedule_delayed_work(&bdev->wq,
 				      ((HZ / 100) < 1) ? 1 : HZ / 100);
 		return;
 	}
 
-	spin_lock(&ttm_glob.lru_lock);
+	spin_lock(&bo->bdev->lru_lock);
 	ttm_bo_del_from_lru(bo);
 	list_del(&bo->ddestroy);
-	spin_unlock(&ttm_glob.lru_lock);
+	spin_unlock(&bo->bdev->lru_lock);
 
 	ttm_bo_cleanup_memtype_use(bo);
 	dma_resv_unlock(bo->base.resv);
@@ -626,7 +625,7 @@ int ttm_mem_evict_first(struct ttm_device *bdev,
 	unsigned i;
 	int ret;
 
-	spin_lock(&ttm_glob.lru_lock);
+	spin_lock(&bo->bdev->lru_lock);
 	for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
 		list_for_each_entry(bo, &man->lru[i], lru) {
 			bool busy;
@@ -663,7 +662,7 @@ int ttm_mem_evict_first(struct ttm_device *bdev,
 	if (!bo) {
 		if (busy_bo && !ttm_bo_get_unless_zero(busy_bo))
 			busy_bo = NULL;
-		spin_unlock(&ttm_glob.lru_lock);
+		spin_unlock(&bo->bdev->lru_lock);
 		ret = ttm_mem_evict_wait_busy(busy_bo, ctx, ticket);
 		if (busy_bo)
 			ttm_bo_put(busy_bo);
@@ -677,7 +676,7 @@ int ttm_mem_evict_first(struct ttm_device *bdev,
 		return ret;
 	}
 
-	spin_unlock(&ttm_glob.lru_lock);
+	spin_unlock(&bo->bdev->lru_lock);
 
 	ret = ttm_bo_evict(bo, ctx);
 	if (locked)
@@ -777,10 +776,9 @@ static int ttm_bo_mem_placement(struct ttm_buffer_object *bo,
 	mem->mem_type = place->mem_type;
 	mem->placement = place->flags;
 
-	spin_lock(&ttm_glob.lru_lock);
+	spin_lock(&bo->bdev->lru_lock);
 	ttm_bo_move_to_lru_tail(bo, mem, NULL);
-	spin_unlock(&ttm_glob.lru_lock);
-
+	spin_unlock(&bo->bdev->lru_lock);
 	return 0;
 }
 
@@ -1167,7 +1165,6 @@ EXPORT_SYMBOL(ttm_bo_wait);
 int ttm_bo_swapout(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx,
 		   gfp_t gfp_flags)
 {
-	struct ttm_global *glob = &ttm_glob;
 	bool locked;
 	int ret;
 
@@ -1188,7 +1185,7 @@ int ttm_bo_swapout(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx,
 
 	ttm_bo_del_from_lru(bo);
 	/* TODO: Cleanup the locking */
-	spin_unlock(&glob->lru_lock);
+	spin_unlock(&bo->bdev->lru_lock);
 
 	/*
 	 * Move to system cached

drivers/gpu/drm/ttm/ttm_device.c

@@ -81,7 +81,6 @@ static int ttm_global_init(void)
 	ttm_pool_mgr_init(num_pages * 50 / 100);
 	ttm_tt_mgr_init();
 
-	spin_lock_init(&glob->lru_lock);
 	glob->dummy_read_page = alloc_page(__GFP_ZERO | GFP_DMA32);
 
 	if (unlikely(glob->dummy_read_page == NULL)) {
@@ -125,13 +124,12 @@ EXPORT_SYMBOL(ttm_global_swapout);
 int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
 		       gfp_t gfp_flags)
 {
-	struct ttm_global *glob = &ttm_glob;
 	struct ttm_resource_manager *man;
 	struct ttm_buffer_object *bo;
 	unsigned i, j;
 	int ret;
 
-	spin_lock(&glob->lru_lock);
+	spin_lock(&bdev->lru_lock);
 	for (i = TTM_PL_SYSTEM; i < TTM_NUM_MEM_TYPES; ++i) {
 		man = ttm_manager_type(bdev, i);
 		if (!man || !man->use_tt)
@@ -156,7 +154,7 @@ int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
 			}
 		}
 	}
-	spin_unlock(&glob->lru_lock);
+	spin_unlock(&bdev->lru_lock);
 	return 0;
 }
 EXPORT_SYMBOL(ttm_device_swapout);
@@ -223,6 +221,7 @@ int ttm_device_init(struct ttm_device *bdev, struct ttm_device_funcs *funcs,
 
 	bdev->vma_manager = vma_manager;
 	INIT_DELAYED_WORK(&bdev->wq, ttm_device_delayed_workqueue);
+	spin_lock_init(&bdev->lru_lock);
 	INIT_LIST_HEAD(&bdev->ddestroy);
 	bdev->dev_mapping = mapping;
 	mutex_lock(&ttm_global_mutex);
@@ -235,7 +234,6 @@ EXPORT_SYMBOL(ttm_device_init);
 
 void ttm_device_fini(struct ttm_device *bdev)
 {
-	struct ttm_global *glob = &ttm_glob;
 	struct ttm_resource_manager *man;
 	unsigned i;
 
@@ -252,11 +250,11 @@ void ttm_device_fini(struct ttm_device *bdev)
 	if (ttm_bo_delayed_delete(bdev, true))
 		pr_debug("Delayed destroy list was clean\n");
 
-	spin_lock(&glob->lru_lock);
+	spin_lock(&bdev->lru_lock);
 	for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i)
 		if (list_empty(&man->lru[0]))
 			pr_debug("Swap list %d was clean\n", i);
-	spin_unlock(&glob->lru_lock);
+	spin_unlock(&bdev->lru_lock);
 
 	ttm_pool_fini(&bdev->pool);
 	ttm_global_release();

drivers/gpu/drm/ttm/ttm_execbuf_util.c

@@ -51,14 +51,12 @@ void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
 	if (list_empty(list))
 		return;
 
-	spin_lock(&ttm_glob.lru_lock);
 	list_for_each_entry(entry, list, head) {
 		struct ttm_buffer_object *bo = entry->bo;
 
-		ttm_bo_move_to_lru_tail(bo, &bo->mem, NULL);
+		ttm_bo_move_to_lru_tail_unlocked(bo);
 		dma_resv_unlock(bo->base.resv);
 	}
-	spin_unlock(&ttm_glob.lru_lock);
 
 	if (ticket)
 		ww_acquire_fini(ticket);
@@ -154,7 +152,6 @@ void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
 	if (list_empty(list))
 		return;
 
-	spin_lock(&ttm_glob.lru_lock);
 	list_for_each_entry(entry, list, head) {
 		struct ttm_buffer_object *bo = entry->bo;
 
@@ -162,10 +159,9 @@ void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
 			dma_resv_add_shared_fence(bo->base.resv, fence);
 		else
 			dma_resv_add_excl_fence(bo->base.resv, fence);
-		ttm_bo_move_to_lru_tail(bo, &bo->mem, NULL);
+		ttm_bo_move_to_lru_tail_unlocked(bo);
 		dma_resv_unlock(bo->base.resv);
 	}
-	spin_unlock(&ttm_glob.lru_lock);
 	if (ticket)
 		ww_acquire_fini(ticket);
 }

drivers/gpu/drm/ttm/ttm_resource.c

@@ -91,7 +91,6 @@ int ttm_resource_manager_evict_all(struct ttm_device *bdev,
 		.no_wait_gpu = false,
 		.force_alloc = true
 	};
-	struct ttm_global *glob = &ttm_glob;
 	struct dma_fence *fence;
 	int ret;
 	unsigned i;
@@ -100,18 +99,18 @@ int ttm_resource_manager_evict_all(struct ttm_device *bdev,
 	 * Can't use standard list traversal since we're unlocking.
 	 */
 
-	spin_lock(&glob->lru_lock);
+	spin_lock(&bdev->lru_lock);
 	for (i = 0; i < TTM_MAX_BO_PRIORITY; ++i) {
 		while (!list_empty(&man->lru[i])) {
-			spin_unlock(&glob->lru_lock);
+			spin_unlock(&bdev->lru_lock);
 			ret = ttm_mem_evict_first(bdev, man, NULL, &ctx,
 						  NULL);
 			if (ret)
 				return ret;
-			spin_lock(&glob->lru_lock);
+			spin_lock(&bdev->lru_lock);
 		}
 	}
-	spin_unlock(&glob->lru_lock);
+	spin_unlock(&bdev->lru_lock);
 
 	spin_lock(&man->move_lock);
 	fence = dma_fence_get(man->move);

include/drm/ttm/ttm_bo_driver.h

@@ -180,9 +180,9 @@ static inline int ttm_bo_reserve_slowpath(struct ttm_buffer_object *bo,
 static inline void
 ttm_bo_move_to_lru_tail_unlocked(struct ttm_buffer_object *bo)
 {
-	spin_lock(&ttm_glob.lru_lock);
+	spin_lock(&bo->bdev->lru_lock);
 	ttm_bo_move_to_lru_tail(bo, &bo->mem, NULL);
-	spin_unlock(&ttm_glob.lru_lock);
+	spin_unlock(&bo->bdev->lru_lock);
 }
 
 static inline void ttm_bo_assign_mem(struct ttm_buffer_object *bo,

include/drm/ttm/ttm_device.h

@@ -56,7 +56,6 @@ extern struct ttm_global {
 	 */
 
 	struct page *dummy_read_page;
-	spinlock_t lru_lock;
 
 	/**
 	 * Protected by ttm_global_mutex.
@@ -277,8 +276,9 @@ struct ttm_device {
 	struct ttm_pool pool;
 
 	/*
-	 * Protected by the global:lru lock.
+	 * Protection for the per manager LRU and ddestroy lists.
 	 */
+	spinlock_t lru_lock;
 	struct list_head ddestroy;
 
 	/*