drm/vmwgfx: Remove the dedicated memory accounting

vmwgfx shared very elaborate memory accounting with ttm. It was moved
from ttm to vmwgfx in change
f07069da6b4c ("drm/ttm: move memory accounting into vmwgfx v4")
but because of complexity it was hard to maintain. Some parts of the code
weren't freeing memory correctly and  some were missing accounting all
together. While those would be fairly easy to fix the fundamental reason
for memory accounting in the driver was the ability to invoke shrinker
which is part of TTM code as well (with support for unified memory
hopefully coming soon).

That meant that vmwgfx had a lot of code that was either unused or
duplicating code from TTM. Removing this code also prevents excessive
calls to global swapout which were common during memory pressure
because both vmwgfx and TTM would invoke the shrinker when memory
usage reached half of RAM.

Fixes: f07069da6b4c ("drm/ttm: move memory accounting into vmwgfx v4")
Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211206172620.3139754-2-zack@kde.org

1 files changed, 2 insertions, 34 deletions

diff --git a/drivers/gpu/drm/vmwgfx/ttm_object.c b/drivers/gpu/drm/vmwgfx/ttm_object.c
index 22b3385d0c37..53de59ce30ca 100644
--- a/drivers/gpu/drm/vmwgfx/ttm_object.c
+++ b/drivers/gpu/drm/vmwgfx/ttm_object.c
@@ -93,10 +93,8 @@ struct ttm_object_device {
 	spinlock_t object_lock;
 	struct vmwgfx_open_hash object_hash;
 	atomic_t object_count;
-	struct ttm_mem_global *mem_glob;
 	struct dma_buf_ops ops;
 	void (*dmabuf_release)(struct dma_buf *dma_buf);
-	size_t dma_buf_size;
 	struct idr idr;
 };
 
@@ -352,11 +350,6 @@ int ttm_ref_object_add(struct ttm_object_file *tfile,
 	struct vmwgfx_open_hash *ht = &tfile->ref_hash[ref_type];
 	struct ttm_ref_object *ref;
 	struct vmwgfx_hash_item *hash;
-	struct ttm_mem_global *mem_glob = tfile->tdev->mem_glob;
-	struct ttm_operation_ctx ctx = {
-		.interruptible = false,
-		.no_wait_gpu = false
-	};
 	int ret = -EINVAL;
 
 	if (base->tfile != tfile && !base->shareable)
@@ -381,13 +374,8 @@ int ttm_ref_object_add(struct ttm_object_file *tfile,
 		if (require_existed)
 			return -EPERM;
 
-		ret = ttm_mem_global_alloc(mem_glob, sizeof(*ref),
-					   &ctx);
-		if (unlikely(ret != 0))
-			return ret;
 		ref = kmalloc(sizeof(*ref), GFP_KERNEL);
 		if (unlikely(ref == NULL)) {
-			ttm_mem_global_free(mem_glob, sizeof(*ref));
 			return -ENOMEM;
 		}
 
@@ -412,7 +400,6 @@ int ttm_ref_object_add(struct ttm_object_file *tfile,
 		spin_unlock(&tfile->lock);
 		BUG_ON(ret != -EINVAL);
 
-		ttm_mem_global_free(mem_glob, sizeof(*ref));
 		kfree(ref);
 	}
 
@@ -427,7 +414,6 @@ ttm_ref_object_release(struct kref *kref)
 	struct ttm_base_object *base = ref->obj;
 	struct ttm_object_file *tfile = ref->tfile;
 	struct vmwgfx_open_hash *ht;
-	struct ttm_mem_global *mem_glob = tfile->tdev->mem_glob;
 
 	ht = &tfile->ref_hash[ref->ref_type];
 	(void)vmwgfx_ht_remove_item_rcu(ht, &ref->hash);
@@ -438,7 +424,6 @@ ttm_ref_object_release(struct kref *kref)
 		base->ref_obj_release(base, ref->ref_type);
 
 	ttm_base_object_unref(&ref->obj);
-	ttm_mem_global_free(mem_glob, sizeof(*ref));
 	kfree_rcu(ref, rcu_head);
 	spin_lock(&tfile->lock);
 }
@@ -526,8 +511,7 @@ out_err:
 }
 
 struct ttm_object_device *
-ttm_object_device_init(struct ttm_mem_global *mem_glob,
-		       unsigned int hash_order,
+ttm_object_device_init(unsigned int hash_order,
 		       const struct dma_buf_ops *ops)
 {
 	struct ttm_object_device *tdev = kmalloc(sizeof(*tdev), GFP_KERNEL);
@@ -536,7 +520,6 @@ ttm_object_device_init(struct ttm_mem_global *mem_glob,
 	if (unlikely(tdev == NULL))
 		return NULL;
 
-	tdev->mem_glob = mem_glob;
 	spin_lock_init(&tdev->object_lock);
 	atomic_set(&tdev->object_count, 0);
 	ret = vmwgfx_ht_create(&tdev->object_hash, hash_order);
@@ -547,8 +530,6 @@ ttm_object_device_init(struct ttm_mem_global *mem_glob,
 	tdev->ops = *ops;
 	tdev->dmabuf_release = tdev->ops.release;
 	tdev->ops.release = ttm_prime_dmabuf_release;
-	tdev->dma_buf_size = ttm_round_pot(sizeof(struct dma_buf)) +
-		ttm_round_pot(sizeof(struct file));
 	return tdev;
 
 out_no_object_hash:
@@ -633,7 +614,6 @@ static void ttm_prime_dmabuf_release(struct dma_buf *dma_buf)
 	if (prime->dma_buf == dma_buf)
 		prime->dma_buf = NULL;
 	mutex_unlock(&prime->mutex);
-	ttm_mem_global_free(tdev->mem_glob, tdev->dma_buf_size);
 	ttm_base_object_unref(&base);
 }
 
@@ -715,30 +695,18 @@ int ttm_prime_handle_to_fd(struct ttm_object_file *tfile,
 	dma_buf = prime->dma_buf;
 	if (!dma_buf || !get_dma_buf_unless_doomed(dma_buf)) {
 		DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
-		struct ttm_operation_ctx ctx = {
-			.interruptible = true,
-			.no_wait_gpu = false
-		};
 		exp_info.ops = &tdev->ops;
 		exp_info.size = prime->size;
 		exp_info.flags = flags;
 		exp_info.priv = prime;
 
 		/*
-		 * Need to create a new dma_buf, with memory accounting.
+		 * Need to create a new dma_buf
 		 */
-		ret = ttm_mem_global_alloc(tdev->mem_glob, tdev->dma_buf_size,
-					   &ctx);
-		if (unlikely(ret != 0)) {
-			mutex_unlock(&prime->mutex);
-			goto out_unref;
-		}
 
 		dma_buf = dma_buf_export(&exp_info);
 		if (IS_ERR(dma_buf)) {
 			ret = PTR_ERR(dma_buf);
-			ttm_mem_global_free(tdev->mem_glob,
-					    tdev->dma_buf_size);
 			mutex_unlock(&prime->mutex);
 			goto out_unref;
 		}