On 13/08/2024 10:44, Lin.Cao wrote:
If buddy manager have more than one roots and each root have sub-block
need to be free. When drm_buddy_fini called, the first loop of
force_merge will merge and free all of the sub block of first root,
which offset is 0x0 and size is biggest(more than have of the mm size).
In subsequent force_merge rounds, if we use 0 as start and use remaining
mm size as end, the block of other roots will be skipped in
__force_merge function. It will cause the other roots can not be freed.
Solution: use roots' offset as the start could fix this issue.
Were you able to take a look at the test side for this? See previous
reply:
https://lore.kernel.org/dri-devel/3fdd9175-832a-4113-8aaa-6039925c5a4d@xxxxxxxxx/
Patch itself is good, but would be good to understand why the test for
this is not failing, and try to improve that also.
Signed-off-by: Lin.Cao <lincao12@xxxxxxx>
---
drivers/gpu/drm/drm_buddy.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
index 94f8c34fc293..b3f0dd652088 100644
--- a/drivers/gpu/drm/drm_buddy.c
+++ b/drivers/gpu/drm/drm_buddy.c
@@ -324,7 +324,7 @@ EXPORT_SYMBOL(drm_buddy_init);
*/
void drm_buddy_fini(struct drm_buddy *mm)
{
- u64 root_size, size;
+ u64 root_size, size, start;
unsigned int order;
int i;
@@ -332,7 +332,8 @@ void drm_buddy_fini(struct drm_buddy *mm)
for (i = 0; i < mm->n_roots; ++i) {
order = ilog2(size) - ilog2(mm->chunk_size);
- __force_merge(mm, 0, size, order);
+ start = drm_buddy_block_offset(mm->roots[i]);
+ __force_merge(mm, start, start + size, order);
WARN_ON(!drm_buddy_block_is_free(mm->roots[i]));
drm_block_free(mm, mm->roots[i]);
