On Thu, Aug 01, 2024 at 04:13:40PM -0700, James Houghton wrote: > --- a/include/linux/mmu_notifier.h > +++ b/include/linux/mmu_notifier.h > @@ -106,6 +106,18 @@ struct mmu_notifier_ops { > * clear_young is a lightweight version of clear_flush_young. Like the > * latter, it is supposed to test-and-clear the young/accessed bitflag > * in the secondary pte, but it may omit flushing the secondary tlb. > + * > + * The fast_only parameter indicates that this call should not block, > + * and this function should not cause other MMU notifier calls to > + * block. Usually this means that the implementation should be > + * lockless. > + * > + * When called with fast_only, this notifier will be a no-op unless > + * has_fast_aging is set on the struct mmu_notifier. If you add a has_fast_aging I wonder if it is better to introduce new ops instead? The semantics are a bit easier to explain that way Jason