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, 0 insertions, 50 deletions

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c
index b15228e7dbeb..a3d39e6b62b8 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c
@@ -175,7 +175,6 @@ struct vmw_ttm_tt {
 	int mem_type;
 	struct sg_table sgt;
 	struct vmw_sg_table vsgt;
-	uint64_t sg_alloc_size;
 	bool mapped;
 	bool bound;
 };
@@ -300,17 +299,10 @@ static int vmw_ttm_map_for_dma(struct vmw_ttm_tt *vmw_tt)
 static int vmw_ttm_map_dma(struct vmw_ttm_tt *vmw_tt)
 {
 	struct vmw_private *dev_priv = vmw_tt->dev_priv;
-	struct ttm_mem_global *glob = vmw_mem_glob(dev_priv);
 	struct vmw_sg_table *vsgt = &vmw_tt->vsgt;
-	struct ttm_operation_ctx ctx = {
-		.interruptible = true,
-		.no_wait_gpu = false
-	};
 	struct vmw_piter iter;
 	dma_addr_t old;
 	int ret = 0;
-	static size_t sgl_size;
-	static size_t sgt_size;
 
 	if (vmw_tt->mapped)
 		return 0;
@@ -324,15 +316,6 @@ static int vmw_ttm_map_dma(struct vmw_ttm_tt *vmw_tt)
 	switch (dev_priv->map_mode) {
 	case vmw_dma_map_bind:
 	case vmw_dma_map_populate:
-		if (unlikely(!sgl_size)) {
-			sgl_size = ttm_round_pot(sizeof(struct scatterlist));
-			sgt_size = ttm_round_pot(sizeof(struct sg_table));
-		}
-		vmw_tt->sg_alloc_size = sgt_size + sgl_size * vsgt->num_pages;
-		ret = ttm_mem_global_alloc(glob, vmw_tt->sg_alloc_size, &ctx);
-		if (unlikely(ret != 0))
-			return ret;
-
 		ret = sg_alloc_table_from_pages_segment(
 			&vmw_tt->sgt, vsgt->pages, vsgt->num_pages, 0,
 			(unsigned long)vsgt->num_pages << PAGE_SHIFT,
@@ -340,15 +323,6 @@ static int vmw_ttm_map_dma(struct vmw_ttm_tt *vmw_tt)
 		if (ret)
 			goto out_sg_alloc_fail;
 
-		if (vsgt->num_pages > vmw_tt->sgt.orig_nents) {
-			uint64_t over_alloc =
-				sgl_size * (vsgt->num_pages -
-					    vmw_tt->sgt.orig_nents);
-
-			ttm_mem_global_free(glob, over_alloc);
-			vmw_tt->sg_alloc_size -= over_alloc;
-		}
-
 		ret = vmw_ttm_map_for_dma(vmw_tt);
 		if (unlikely(ret != 0))
 			goto out_map_fail;
@@ -375,7 +349,6 @@ out_map_fail:
 	sg_free_table(vmw_tt->vsgt.sgt);
 	vmw_tt->vsgt.sgt = NULL;
 out_sg_alloc_fail:
-	ttm_mem_global_free(glob, vmw_tt->sg_alloc_size);
 	return ret;
 }
 
@@ -401,8 +374,6 @@ static void vmw_ttm_unmap_dma(struct vmw_ttm_tt *vmw_tt)
 		vmw_ttm_unmap_from_dma(vmw_tt);
 		sg_free_table(vmw_tt->vsgt.sgt);
 		vmw_tt->vsgt.sgt = NULL;
-		ttm_mem_global_free(vmw_mem_glob(dev_priv),
-				    vmw_tt->sg_alloc_size);
 		break;
 	default:
 		break;
@@ -522,7 +493,6 @@ static void vmw_ttm_destroy(struct ttm_device *bdev, struct ttm_tt *ttm)
 static int vmw_ttm_populate(struct ttm_device *bdev,
 			    struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
 {
-	unsigned int i;
 	int ret;
 
 	/* TODO: maybe completely drop this ? */
@@ -530,22 +500,7 @@ static int vmw_ttm_populate(struct ttm_device *bdev,
 		return 0;
 
 	ret = ttm_pool_alloc(&bdev->pool, ttm, ctx);
-	if (ret)
-		return ret;
-
-	for (i = 0; i < ttm->num_pages; ++i) {
-		ret = ttm_mem_global_alloc_page(&ttm_mem_glob, ttm->pages[i],
-						PAGE_SIZE, ctx);
-		if (ret)
-			goto error;
-	}
-	return 0;
 
-error:
-	while (i--)
-		ttm_mem_global_free_page(&ttm_mem_glob, ttm->pages[i],
-					 PAGE_SIZE);
-	ttm_pool_free(&bdev->pool, ttm);
 	return ret;
 }
 
@@ -554,7 +509,6 @@ static void vmw_ttm_unpopulate(struct ttm_device *bdev,
 {
 	struct vmw_ttm_tt *vmw_tt = container_of(ttm, struct vmw_ttm_tt,
 						 dma_ttm);
-	unsigned int i;
 
 	vmw_ttm_unbind(bdev, ttm);
 
@@ -565,10 +519,6 @@ static void vmw_ttm_unpopulate(struct ttm_device *bdev,
 
 	vmw_ttm_unmap_dma(vmw_tt);
 
-	for (i = 0; i < ttm->num_pages; ++i)
-		ttm_mem_global_free_page(&ttm_mem_glob, ttm->pages[i],
-					 PAGE_SIZE);
-
 	ttm_pool_free(&bdev->pool, ttm);
 }