On Fri, 2022-07-08 at 07:51 -0700, Niranjana Vishwanathapura wrote: > > Since we don't loop over the vm_bound_list, there is a need to > > check > > whether the rebind_list is empty here under the notifier_lock in > > read > > mode, and in that case, restart from eb_lookup_vmas(). That might > > also > > eliminate the need for the __EXEC3_USERPTR_USED flag? > > > > That will also catch any objects that were evicted between > > eb_lookup_vmas() where the rebind_list was last checked, and > > i915_gem_vm_priv_lock(), which prohibits further eviction, but if > > we > > want to catch these earlier (which I think is a good idea), we > > could > > check that the rebind_list is indeed empty just after taking the > > vm_priv_lock(), and if not, restart from eb_lookup_vmas(). > > Yah, right, we need to check rebind_list here and if not empty, > restart > from lookup phase. > It is bit tricky with userptr here as the unbind happens during > submit_init() call after we scoop unbound vmas here, the vmas gets > re-added to rebind_list :(. Ugh. > I think we need a separate 'invalidated_userptr_list' here and we > iterate through it for submit_init() and submit_done() calls (yes, > __EXEC3_USERPTR_USED flag won't be needed then). > And, we call, eb_scoop_unbound_vmas() after calling > eb_lookup_persistent_userptr_vmas(), so that we scoop all unbound > vmas properly. > I'm not sure that will help much, because we'd also need to recheck the rebind_list and possibly restart after taking the vm_priv_lock, since objects can be evicted between the scooping and taking the vm_priv_lock. So then the userptrs will be caught by that check. /Thomas
