Allocating small bos from one end and large ones from the other helps
improve the quality of fragmentation.
I have measured a suitable threshold to reduce eviction by up to 20%,
and to cause no harm in normal cases that fit VRAM fully (PTS gaming suite).
In some cases, even the VRAM-fitting cases improved slightly (openarena, urban
terror).
This depends on "drm: Optionally create mm blocks from top-to-bottom" by
Chris Wilson, and so is just RFC for now.
---
drivers/gpu/drm/ttm/ttm_bo.c | 4 +++-
drivers/gpu/drm/ttm/ttm_bo_manager.c | 12 +++++++++---
include/drm/ttm/ttm_bo_driver.h | 5 ++++-
3 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index a066513..7f30c2d 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -1450,7 +1450,8 @@ int ttm_bo_device_init(struct ttm_bo_device *bdev,
struct ttm_bo_global *glob,
struct ttm_bo_driver *driver,
uint64_t file_page_offset,
- bool need_dma32)
+ bool need_dma32,
+ uint32_t alloc_threshold)
{
int ret = -EINVAL;
@@ -1473,6 +1474,7 @@ int ttm_bo_device_init(struct ttm_bo_device *bdev,
bdev->dev_mapping = NULL;
bdev->glob = glob;
bdev->need_dma32 = need_dma32;
+ bdev->alloc_threshold = alloc_threshold;
bdev->val_seq = 0;
spin_lock_init(&bdev->fence_lock);
mutex_lock(&glob->device_list_mutex);
diff --git a/drivers/gpu/drm/ttm/ttm_bo_manager.c
b/drivers/gpu/drm/ttm/ttm_bo_manager.c
index c58eba33..bd1cbf1 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_manager.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_manager.c
@@ -55,6 +55,7 @@ static int ttm_bo_man_get_node(struct ttm_mem_type_manager
*man,
struct ttm_range_manager *rman = (struct ttm_range_manager *) man->priv;
struct drm_mm *mm = &rman->mm;
struct drm_mm_node *node = NULL;
+ enum drm_mm_allocator_flags aflags = DRM_MM_CREATE_DEFAULT;
unsigned long lpfn;
int ret;
@@ -66,11 +67,16 @@ static int ttm_bo_man_get_node(struct ttm_mem_type_manager
*man,
if (!node)
return -ENOMEM;
+ if (man->bdev->alloc_threshold &&
+ man->bdev->alloc_threshold < (mem->num_pages * PAGE_SIZE))
+ aflags = DRM_MM_CREATE_TOP;
+
spin_lock(&rman->lock);
- ret = drm_mm_insert_node_in_range(mm, node, mem->num_pages,
- mem->page_alignment,
+ ret = drm_mm_insert_node_in_range_generic(mm, node, mem->num_pages,
+ mem->page_alignment, 0,
placement->fpfn, lpfn,
- DRM_MM_SEARCH_BEST);
+ DRM_MM_SEARCH_BEST,
+ aflags);
spin_unlock(&rman->lock);
if (unlikely(ret)) {
diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
index 32d34eb..831320e 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -565,6 +565,7 @@ struct ttm_bo_device {
struct delayed_work wq;
bool need_dma32;
+ uint32_t alloc_threshold;
};
/**
@@ -758,7 +759,9 @@ extern int ttm_bo_device_release(struct ttm_bo_device
*bdev);
extern int ttm_bo_device_init(struct ttm_bo_device *bdev,
struct ttm_bo_global *glob,
struct ttm_bo_driver *driver,
- uint64_t file_page_offset, bool need_dma32);
+ uint64_t file_page_offset,
+ bool need_dma32,
+ uint32_t alloc_threshold);
/**
* ttm_bo_unmap_virtual
--
1.8.3.1
