PGD_SIZE
static pgd_t tmp_pgd_table[PTRS_PER_PGD] __initdata __aligned(PGD_SIZE);
memset(tramp_pg_dir, 0, PGD_SIZE);
if (PGD_SIZE == PAGE_SIZE)
BUILD_BUG_ON(!IS_ALIGNED(PGD_SIZE, 64));
pgd_cache = kmem_cache_create("pgd_cache", PGD_SIZE, PGD_SIZE,