Hi Christian In amdgpu_cs_parser_bos(), it calls ttm_eu_backoff_reservation() if @need_pages not empty, is it safe ? You see that if two threads in parallel running in cs_parser_bos(), if the thread1 did call backoff_reservation and continue, that leaves All following reservation functions on root BO executed without protection from the lock, Meanwhile if this time thread2 call cs_parser_bos() in parallel, it can Get the lock of the reservation object on root BO (assume thread 1/2 share the same VM) immediately, so both of those threads consider they are Under protection of lock of reservation on the root bo. Do you think it's a race issue ? You know that I recently hit BUG() in reservation.c, and also found some weird bugs can be fixed by removing the kfree(obj->staged) In reservation_object_reserve_shared(), and I think you right on the "staged" part that it shouldn't be freed if everything go with rules ( Always held the lock of the bo) Thanks /Monk -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://lists.freedesktop.org/archives/amd-gfx/attachments/20180228/756e07eb/attachment.html>
