On Fri, May 26, 2023 at 05:44:26PM -0600, Yu Zhao wrote: > @@ -122,6 +124,10 @@ struct mmu_notifier_ops { > struct mm_struct *mm, > unsigned long address); > > + int (*test_clear_young)(struct mmu_notifier *mn, struct mm_struct *mm, > + unsigned long start, unsigned long end, > + bool clear, unsigned long *bitmap); > + Why leave clear_young behind? Just make a NULL bitmap mean clear_young? Jason