Hi Oscar,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on tip/x86/mm]
[also build test ERROR on hnaz-linux-mm/master v5.11-rc6 next-20210125]
[cannot apply to luto/next]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Oscar-Salvador/Cleanup-and-fixups-for-vmemmap-handling/20210202-192636
base:   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 167dcfc08b0b1f964ea95d410aa496fd78adf475
config: x86_64-randconfig-r004-20210202 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 275c6af7d7f1ed63a03d05b4484413e447133269)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install x86_64 cross compiling tool for clang build
        # apt-get install binutils-x86-64-linux-gnu
        # https://github.com/0day-ci/linux/commit/2995155f4651bbb8c0d5f2e58e6e77321c5a889a
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Oscar-Salvador/Cleanup-and-fixups-for-vmemmap-handling/20210202-192636
        git checkout 2995155f4651bbb8c0d5f2e58e6e77321c5a889a
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <redacted>

All errors (new ones prefixed by >>):

quoted

arch/x86/mm/init_64.c:1588:6: error: implicit declaration of function 'vmemmap_use_new_sub_pmd' [-Werror,-Wimplicit-function-declaration]

                                           vmemmap_use_new_sub_pmd(addr, next);
                                           ^

quoted

arch/x86/mm/init_64.c:1594:4: error: implicit declaration of function 'vmemmap_use_sub_pmd' [-Werror,-Wimplicit-function-declaration]

                           vmemmap_use_sub_pmd(addr, next);
                           ^
   2 errors generated.


vim +/vmemmap_use_new_sub_pmd +1588 arch/x86/mm/init_64.c

  1535	
  1536	static int __meminit vmemmap_populate_hugepages(unsigned long start,
  1537			unsigned long end, int node, struct vmem_altmap *altmap)
  1538	{
  1539		unsigned long addr;
  1540		unsigned long next;
  1541		pgd_t *pgd;
  1542		p4d_t *p4d;
  1543		pud_t *pud;
  1544		pmd_t *pmd;
  1545	
  1546		for (addr = start; addr < end; addr = next) {
  1547			next = pmd_addr_end(addr, end);
  1548	
  1549			pgd = vmemmap_pgd_populate(addr, node);
  1550			if (!pgd)
  1551				return -ENOMEM;
  1552	
  1553			p4d = vmemmap_p4d_populate(pgd, addr, node);
  1554			if (!p4d)
  1555				return -ENOMEM;
  1556	
  1557			pud = vmemmap_pud_populate(p4d, addr, node);
  1558			if (!pud)
  1559				return -ENOMEM;
  1560	
  1561			pmd = pmd_offset(pud, addr);
  1562			if (pmd_none(*pmd)) {
  1563				void *p;
  1564	
  1565				p = vmemmap_alloc_block_buf(PMD_SIZE, node, altmap);
  1566				if (p) {
  1567					pte_t entry;
  1568	
  1569					entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
  1570							PAGE_KERNEL_LARGE);
  1571					set_pmd(pmd, __pmd(pte_val(entry)));
  1572	
  1573					/* check to see if we have contiguous blocks */
  1574					if (p_end != p || node_start != node) {
  1575						if (p_start)
  1576							pr_debug(" [%lx-%lx] PMD -> [%p-%p] on node %d\n",
  1577							       addr_start, addr_end-1, p_start, p_end-1, node_start);
  1578						addr_start = addr;
  1579						node_start = node;
  1580						p_start = p;
  1581					}
  1582	
  1583					addr_end = addr + PMD_SIZE;
  1584					p_end = p + PMD_SIZE;
  1585	
  1586					if (!IS_ALIGNED(addr, PMD_SIZE) ||
  1587					    !IS_ALIGNED(next, PMD_SIZE))

1588						vmemmap_use_new_sub_pmd(addr, next);

  1589					continue;
  1590				} else if (altmap)
  1591					return -ENOMEM; /* no fallback */
  1592			} else if (pmd_large(*pmd)) {
  1593				vmemmap_verify((pte_t *)pmd, node, addr, next);

1594				vmemmap_use_sub_pmd(addr, next);

  1595				continue;
  1596			}
  1597			if (vmemmap_populate_basepages(addr, next, node, NULL))
  1598				return -ENOMEM;
  1599		}
  1600		return 0;
  1601	}
  1602	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org