On 08/02/2024 15:50, Arunpravin Paneer Selvam wrote:
Add a function to support defragmentation.
v1: Defragment the memory beginning from min_order
till the required memory space is available.
Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@xxxxxxx>
Suggested-by: Matthew Auld <matthew.auld@xxxxxxxxx>
---
drivers/gpu/drm/drm_buddy.c | 67 +++++++++++++++++++++++++++++++------
include/drm/drm_buddy.h | 3 ++
No users?
2 files changed, 59 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
index 33ad0cfbd54c..fac423d2cb73 100644
--- a/drivers/gpu/drm/drm_buddy.c
+++ b/drivers/gpu/drm/drm_buddy.c
@@ -276,10 +276,12 @@ 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)
{
struct drm_buddy_block *parent;
+ unsigned int order;
while ((parent = block->parent)) {
struct drm_buddy_block *buddy;
@@ -289,12 +291,14 @@ static void __drm_buddy_free(struct drm_buddy *mm,
if (!drm_buddy_block_is_free(buddy))
break;
- if (drm_buddy_block_is_clear(block) !=
- drm_buddy_block_is_clear(buddy))
- break;
+ if (!defrag) {
+ 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);
+ }
Maybe check if the two blocks are incompatible and chuck a warn if they
are not? Main thing is not to hide issues with split blocks that should
have been merged before.
list_del(&buddy->link);
@@ -304,8 +308,49 @@ static void __drm_buddy_free(struct drm_buddy *mm,
block = parent;
}
+ order = drm_buddy_block_order(block);
mark_free(mm, block);
+
+ return order;
+}
+
+/**
+ * drm_buddy_defrag - Defragmentation routine
+ *
+ * @mm: DRM buddy manager
+ * @min_order: minimum order in the freelist 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_order)
Just wondering if we need "full defag" also? We would probably need to
call this at fini() anyway.
+{
+ struct drm_buddy_block *block;
+ struct list_head *list;
+ unsigned int order;
+ int i;
+
+ if (min_order > mm->max_order)
+ return;
+
+ for (i = min_order - 1; i >= 0; i--) {
Need to be careful with min_order = 0 ?
+ list = &mm->free_list[i];
+ if (list_empty(list))
+ continue;
+
+ list_for_each_entry_reverse(block, list, link) {
Don't we need the safe_reverse() variant here, since this is removing
from the list?
+ 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 +366,7 @@ 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);
@@ -470,7 +515,7 @@ __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);
}
@@ -588,7 +633,7 @@ 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);
}
@@ -668,7 +713,7 @@ 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) {
diff --git a/include/drm/drm_buddy.h b/include/drm/drm_buddy.h
index d81c596dfa38..d0f63e7b5915 100644
--- a/include/drm/drm_buddy.h
+++ b/include/drm/drm_buddy.h
@@ -166,6 +166,9 @@ 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,
