Hi!
I might be misunderderstanding the use-case here, but IIRC the discussion with TTM vs imported / exported buffer objects is that a buffer object needs to be marked NO_EVICT in TTM before it's exported and an imported object should never end up on a LRU list in TTM because TTM wouldn't know how to evict it.
/Thomas
On 01/08/2016 02:41 PM, Christian König wrote:
From: Christian König christian.koenig@amd.com
If we import a BO with an eternal reservation object we don't reserve/unreserve it. So we never add it to the LRU causing a possible deny of service.
Signed-off-by: Christian König christian.koenig@amd.com
drivers/gpu/drm/ttm/ttm_bo.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c index 745e996..a98a5d5 100644 --- a/drivers/gpu/drm/ttm/ttm_bo.c +++ b/drivers/gpu/drm/ttm/ttm_bo.c @@ -1170,9 +1170,15 @@ int ttm_bo_init(struct ttm_bo_device *bdev, if (likely(!ret)) ret = ttm_bo_validate(bo, placement, interruptible, false);
- if (!resv)
if (!resv) { ttm_bo_unreserve(bo);
} else if (!(bo->mem.placement & TTM_PL_FLAG_NO_EVICT)) {
spin_lock(&bo->glob->lru_lock);ttm_bo_add_to_lru(bo);spin_unlock(&bo->glob->lru_lock);}
if (unlikely(ret)) ttm_bo_unref(&bo);