On 07/03/22 9:23 pm, Christian König wrote:
Am 07.03.22 um 15:37 schrieb Arunpravin:
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.
Well using BUG_ON sounds like the wrong approach in the first place.
A BUG_ON() is only justified if you prevent further data corruption, e.g. when you detect for example a reference count overflow or similar.
In all other cases you should trigger a WARN_ON() and abort the operation with -EINVAL if possible.
Regards, Christian.
ok, in this case, I think it is acceptable to use WARN_ON and abort using -EINVAL
Regards, Arun
Signed-off-by: Arunpravin Arunpravin.PaneerSelvam@amd.com
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);
- 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