On 07/03/2022 14:37, Arunpravin wrote:
place BUG_ON(order < min_order) outside do..while
loop as it fails Unigine Heaven benchmark.
Unigine Heaven has buffer allocation requests for
example required pages are 161 and alignment request
is 128. To allocate the remaining 33 pages, continues
the iteration to find the order value which is 5 and
when it compares with min_order = 7, enables the
BUG_ON(). To avoid this problem, placed the BUG_ON
check outside of do..while loop.
Signed-off-by: Arunpravin <Arunpravin.PaneerSelvam@xxxxxxx>
---
drivers/gpu/drm/drm_buddy.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
index 72f52f293249..ed94c56b720f 100644
--- a/drivers/gpu/drm/drm_buddy.c
+++ b/drivers/gpu/drm/drm_buddy.c
@@ -669,10 +669,11 @@ int drm_buddy_alloc_blocks(struct drm_buddy *mm,
order = fls(pages) - 1;
min_order = ilog2(min_page_size) - ilog2(mm->chunk_size);
+ BUG_ON(order < min_order);
Isn't the issue that we are allowing a size that is not aligned to the
requested min_page_size? Should we not fix the caller(and throw a normal
error here), or perhaps add the round_up() here instead?
i.e if someone does:
alloc_blocks(mm, 0, end, 4096, 1<<16, &blocks, flags);
This will still trigger the BUG_ON() even if we move it out of the loop,
AFAICT.
+
do {
order = min(order, (unsigned int)fls(pages) - 1);
BUG_ON(order > mm->max_order);
- BUG_ON(order < min_order);
do {
if (flags & DRM_BUDDY_RANGE_ALLOCATION)
base-commit: 8025c79350b90e5a8029234d433578f12abbae2b
