PKMAP_NR 191 mm/highmem.c pkmap_count[PKMAP_NR(vaddr)]++; PKMAP_NR 192 mm/highmem.c BUG_ON(pkmap_count[PKMAP_NR(vaddr)] < 2); PKMAP_NR 212 mm/highmem.c nr = PKMAP_NR(vaddr);