linux/mm/vmscan.c

3260 	unsigned long new_flags, old_flags = READ_ONCE(folio->flags);
3272 		if (!(old_flags & LRU_GEN_MASK))
3275 		new_flags = old_flags & ~(LRU_GEN_MASK | LRU_REFS_FLAGS);
3277 	} while (!try_cmpxchg(&folio->flags, &old_flags, new_flags));
3279 	return ((old_flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;
3288 	unsigned long new_flags, old_flags = READ_ONCE(folio->flags);
3290 	VM_WARN_ON_ONCE_FOLIO(!(old_flags & LRU_GEN_MASK), folio);
3293 		new_gen = ((old_flags & LRU_GEN_MASK) >> LRU_GEN_PGOFF) - 1;
3300 		new_flags = old_flags & ~(LRU_GEN_MASK | LRU_REFS_FLAGS);
3305 	} while (!try_cmpxchg(&folio->flags, &old_flags, new_flags));