Am 06.05.24 um 11:46 schrieb Thomas Hellström:
Hi Christian, Others. In order to support exhaustive eviction there are some changes that I think needs to be made to drm_exec: 1) Trylock support (This is for ttm_bo_vm, ttm_buffer_object_init_reserved, and also for the eviction path where I think we want to make a trylock pass before a sleeping lock pass).
Not sure why we need this for ttm_bo_vm, but in general that sounds like the right approach to me as well.
In essence this means we can't leave any contending lock unlocked until the next sleeping lock, but rather need to relock it on drm_exec_retry_on_contention(), meaning that that macro also gets passed and returns an error code to handle -EINTR.
Hui what? I can't really follow what you mean here.
2) Snapshot unlock After successfully obtaining backing store, we want to unlock all evicted objects. So snapshot the drm_exec state when eviction begins, and unlock everything down to the snapshot after successful backing store allocation. Essentially the snapshot contains the number of locked objects and a pointer to the prelocked object.
Interesting idea, never though about that. Not sure if that makes the situation better or worse.
One goal of drm_exec was to be able to keep evicted BOs locked until the whole submission is completed and that obviously contradicts that.
Regards, Christian.
Any concerns? Thanks, Thomas
