[PATCH v7 3/3] drm/buddy: Add defragmentation support
Arunpravin Paneer Selvam
Arunpravin.PaneerSelvam at amd.com
Wed Feb 21 12:18:01 UTC 2024
Add a function to support defragmentation.
v1:
- Defragment the memory beginning from min_order
till the required memory space is available.
v2(Matthew):
- add amdgpu user for defragmentation
- add a warning if the two blocks are incompatible on
defragmentation
- call full defragmentation in the fini() function
- place a condition to test if min_order is equal to 0
- replace the list with safe_reverse() variant as we might
remove the block from the list.
Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam at amd.com>
Suggested-by: Matthew Auld <matthew.auld at intel.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 17 +++-
drivers/gpu/drm/drm_buddy.c | 93 +++++++++++++++++---
include/drm/drm_buddy.h | 3 +
3 files changed, 97 insertions(+), 16 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
index e494f5bf136a..cff8a526c622 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -533,8 +533,21 @@ static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
min_block_size,
&vres->blocks,
vres->flags);
- if (unlikely(r))
- goto error_free_blocks;
+ if (unlikely(r)) {
+ if (r == -ENOSPC) {
+ drm_buddy_defrag(mm, min_block_size);
+ r = drm_buddy_alloc_blocks(mm, fpfn,
+ lpfn,
+ size,
+ min_block_size,
+ &vres->blocks,
+ vres->flags);
+ if (unlikely(r))
+ goto error_free_blocks;
+ } else {
+ goto error_free_blocks;
+ }
+ }
if (size > remaining_size)
remaining_size = 0;
diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
index 18e004fa39d3..56bd1560fbcd 100644
--- a/drivers/gpu/drm/drm_buddy.c
+++ b/drivers/gpu/drm/drm_buddy.c
@@ -203,6 +203,8 @@ void drm_buddy_fini(struct drm_buddy *mm)
drm_block_free(mm, mm->roots[i]);
}
+ drm_buddy_defrag(mm, mm->chunk_size << mm->max_order);
+
WARN_ON(mm->avail != mm->size);
kfree(mm->roots);
@@ -276,25 +278,39 @@ drm_get_buddy(struct drm_buddy_block *block)
}
EXPORT_SYMBOL(drm_get_buddy);
-static void __drm_buddy_free(struct drm_buddy *mm,
- struct drm_buddy_block *block)
+static unsigned int __drm_buddy_free(struct drm_buddy *mm,
+ struct drm_buddy_block *block,
+ bool defrag)
{
+ unsigned int order, block_order;
struct drm_buddy_block *parent;
+ block_order = drm_buddy_block_order(block);
+
while ((parent = block->parent)) {
- struct drm_buddy_block *buddy;
+ struct drm_buddy_block *buddy = NULL;
buddy = __get_buddy(block);
if (!drm_buddy_block_is_free(buddy))
break;
- if (drm_buddy_block_is_clear(block) !=
- drm_buddy_block_is_clear(buddy))
- break;
+ if (!defrag) {
+ /*
+ * Check the block and its buddy clear state and exit
+ * the loop if they both have the dissimilar state.
+ */
+ if (drm_buddy_block_is_clear(block) !=
+ drm_buddy_block_is_clear(buddy))
+ break;
- if (drm_buddy_block_is_clear(block))
- mark_cleared(parent);
+ if (drm_buddy_block_is_clear(block))
+ mark_cleared(parent);
+ }
+
+ WARN_ON(defrag &&
+ (drm_buddy_block_is_clear(block) ==
+ drm_buddy_block_is_clear(buddy)));
list_del(&buddy->link);
@@ -304,8 +320,57 @@ static void __drm_buddy_free(struct drm_buddy *mm,
block = parent;
}
- mark_free(mm, block);
+ order = drm_buddy_block_order(block);
+ if (block_order != order)
+ mark_free(mm, block);
+
+ return order;
+}
+
+/**
+ * drm_buddy_defrag - Defragmentation routine
+ *
+ * @mm: DRM buddy manager
+ * @min_block_size: minimum size in bytes to begin
+ * the defragmentation process
+ *
+ * Driver calls the defragmentation function when the
+ * requested memory allocation returns -ENOSPC.
+ */
+void drm_buddy_defrag(struct drm_buddy *mm,
+ unsigned int min_block_size)
+{
+ struct drm_buddy_block *block, *tmp;
+ unsigned int order, min_order;
+ struct list_head *list;
+ unsigned long pages;
+ int i;
+
+ pages = min_block_size >> ilog2(mm->chunk_size);
+ min_order = fls(pages) - 1;
+
+ if (!min_order)
+ return;
+
+ if (min_order > mm->max_order)
+ return;
+
+ for (i = min_order - 1; i >= 0; i--) {
+ list = &mm->free_list[i];
+ if (list_empty(list))
+ continue;
+
+ list_for_each_entry_safe_reverse(block, tmp, list, link) {
+ if (!block->parent)
+ continue;
+
+ order = __drm_buddy_free(mm, block, 1);
+ if (order >= min_order)
+ return;
+ }
+ }
}
+EXPORT_SYMBOL(drm_buddy_defrag);
/**
* drm_buddy_free_block - free a block
@@ -321,7 +386,7 @@ void drm_buddy_free_block(struct drm_buddy *mm,
if (drm_buddy_block_is_clear(block))
mm->clear_avail += drm_buddy_block_size(mm, block);
- __drm_buddy_free(mm, block);
+ __drm_buddy_free(mm, block, 0);
}
EXPORT_SYMBOL(drm_buddy_free_block);
@@ -468,7 +533,7 @@ __alloc_range_bias(struct drm_buddy *mm,
if (buddy &&
(drm_buddy_block_is_free(block) &&
drm_buddy_block_is_free(buddy)))
- __drm_buddy_free(mm, block);
+ __drm_buddy_free(mm, block, 0);
return ERR_PTR(err);
}
@@ -586,7 +651,7 @@ alloc_from_freelist(struct drm_buddy *mm,
err_undo:
if (tmp != order)
- __drm_buddy_free(mm, block);
+ __drm_buddy_free(mm, block, 0);
return ERR_PTR(err);
}
@@ -666,7 +731,7 @@ static int __alloc_range(struct drm_buddy *mm,
if (buddy &&
(drm_buddy_block_is_free(block) &&
drm_buddy_block_is_free(buddy)))
- __drm_buddy_free(mm, block);
+ __drm_buddy_free(mm, block, 0);
err_free:
if (err == -ENOSPC && total_allocated_on_err) {
@@ -828,7 +893,7 @@ EXPORT_SYMBOL(drm_buddy_block_trim);
* @mm: DRM buddy manager to allocate from
* @start: start of the allowed range for this block
* @end: end of the allowed range for this block
- * @size: size of the allocation
+ * @size: size of the allocation in bytes
* @min_block_size: alignment of the allocation
* @blocks: output list head to add allocated blocks
* @flags: DRM_BUDDY_*_ALLOCATION flags
diff --git a/include/drm/drm_buddy.h b/include/drm/drm_buddy.h
index 352a6364e26a..68a874846e78 100644
--- a/include/drm/drm_buddy.h
+++ b/include/drm/drm_buddy.h
@@ -167,6 +167,9 @@ void drm_buddy_free_list(struct drm_buddy *mm,
struct list_head *objects,
unsigned int flags);
+void drm_buddy_defrag(struct drm_buddy *mm,
+ unsigned int min_order);
+
void drm_buddy_print(struct drm_buddy *mm, struct drm_printer *p);
void drm_buddy_block_print(struct drm_buddy *mm,
struct drm_buddy_block *block,
--
2.25.1
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