[PATCH] drm/ttm: Break out the loops if need_resched in bo delayed delete worker

[xinhui pan]

The delayed delete list is per device which might be very huge. And in
a heavy workload test, the list might always not be empty. That will
trigger any RCU stall warnings or softlockups in non-preemptible kernels
Lets do break out the loops in that case.

Signed-off-by: xinhui pan <xinhui.pan at amd.com>
---
 drivers/gpu/drm/ttm/ttm_bo.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 9e07c3f75156..c5b516fa4eae 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -518,7 +518,7 @@ static bool ttm_bo_delayed_delete(struct ttm_bo_device *bdev, bool remove_all)
 	INIT_LIST_HEAD(&removed);
 
 	spin_lock(&glob->lru_lock);
-	while (!list_empty(&bdev->ddestroy)) {
+	while (!list_empty(&bdev->ddestroy) && !need_resched()) {
 		struct ttm_buffer_object *bo;
 
 		bo = list_first_entry(&bdev->ddestroy, struct ttm_buffer_object,
-- 
2.17.1