drm: Memory fragmentation from lost alignment blocks

If the block needs an alignment but otherwise fits exactly into the tail,
then the split-off block from the start would remain marked as non-free.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Chris Wilson 2009-05-22 14:14:22 +01:00 committed by Dave Airlie
parent 602c11a8ee
commit e6c03c5b40
1 changed files with 9 additions and 11 deletions

View File

@ -188,36 +188,34 @@ static struct drm_mm_node *drm_mm_split_at_start(struct drm_mm_node *parent,
struct drm_mm_node *drm_mm_get_block(struct drm_mm_node * parent,
unsigned long size, unsigned alignment)
struct drm_mm_node *drm_mm_get_block(struct drm_mm_node *node,
unsigned long size, unsigned alignment)
{
struct drm_mm_node *align_splitoff = NULL;
struct drm_mm_node *child;
unsigned tmp = 0;
if (alignment)
tmp = parent->start % alignment;
tmp = node->start % alignment;
if (tmp) {
align_splitoff =
drm_mm_split_at_start(parent, alignment - tmp, 0);
drm_mm_split_at_start(node, alignment - tmp, 0);
if (unlikely(align_splitoff == NULL))
return NULL;
}
if (parent->size == size) {
list_del_init(&parent->fl_entry);
parent->free = 0;
return parent;
if (node->size == size) {
list_del_init(&node->fl_entry);
node->free = 0;
} else {
child = drm_mm_split_at_start(parent, size, 0);
node = drm_mm_split_at_start(node, size, 0);
}
if (align_splitoff)
drm_mm_put_block(align_splitoff);
return child;
return node;
}
EXPORT_SYMBOL(drm_mm_get_block);