Hi Baolin,

I love your patch! Yet something to improve:

[auto build test ERROR on next-20211220]
[cannot apply to hnaz-mm/master linux/master linus/master v5.16-rc6 v5.16-rc5 v5.16-rc4 v5.16-rc6]
[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/Baolin-Wang/Add-a-new-scheme-to-support-demotion-on-tiered-memory-system/20211221-172017
base:    07f8c60fe60f84977dc815ec8a6b1100827c34dd
config: arc-randconfig-r043-20211222 (https://download.01.org/0day-ci/archive/20211222/202112221923.4m9tlPoy-lkp@intel.com/config)
compiler: arc-elf-gcc (GCC) 11.2.0
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
        # https://github.com/0day-ci/linux/commit/ed1c1ea9c5b5ea81916c10e50c4a1613bce4b5a9
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Baolin-Wang/Add-a-new-scheme-to-support-demotion-on-tiered-memory-system/20211221-172017
        git checkout ed1c1ea9c5b5ea81916c10e50c4a1613bce4b5a9
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=arc SHELL=/bin/bash

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

   mm/damon/vaddr.c: In function 'damos_migrate_pmd_entry':
>> mm/damon/vaddr.c:635:14: error: implicit declaration of function 'vma_migratable'; did you mean 'HPageMigratable'? [-Werror=implicit-function-declaration]
     635 |         if (!vma_migratable(vma))
         |              ^~~~~~~~~~~~~~
         |              HPageMigratable
>> mm/damon/vaddr.c:648:39: error: implicit declaration of function 'pmd_pfn'; did you mean 'pmd_off'? [-Werror=implicit-function-declaration]
     648 |                 page = damon_get_page(pmd_pfn(*pmd));
         |                                       ^~~~~~~
         |                                       pmd_off
   cc1: some warnings being treated as errors


vim +635 mm/damon/vaddr.c

   625	
   626	static int damos_migrate_pmd_entry(pmd_t *pmd, unsigned long addr,
   627					   unsigned long end, struct mm_walk *walk)
   628	{
   629		struct vm_area_struct *vma = walk->vma;
   630		struct list_head *demote_list = walk->private;
   631		spinlock_t *ptl;
   632		struct page *page;
   633		pte_t *pte, *mapped_pte;
   634	
 > 635		if (!vma_migratable(vma))
   636			return -EFAULT;
   637	
   638		ptl = pmd_trans_huge_lock(pmd, vma);
   639		if (ptl) {
   640			/* Bail out if THP migration is not supported. */
   641			if (!thp_migration_supported())
   642				goto thp_out;
   643	
   644			/* If the THP pte is under migration, do not bother it. */
   645			if (unlikely(is_pmd_migration_entry(*pmd)))
   646				goto thp_out;
   647	
 > 648			page = damon_get_page(pmd_pfn(*pmd));
   649			if (!page)
   650				goto thp_out;
   651	
   652			damos_isolate_page(page, demote_list);
   653	
   654			put_page(page);
   655	thp_out:
   656			spin_unlock(ptl);
   657			return 0;
   658		}
   659	
   660		/* regular page handling */
   661		if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
   662			return -EINVAL;
   663	
   664		mapped_pte = pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
   665		for (; addr != end; pte++, addr += PAGE_SIZE) {
   666			if (pte_none(*pte) || !pte_present(*pte))
   667				continue;
   668	
   669			page = damon_get_page(pte_pfn(*pte));
   670			if (!page)
   671				continue;
   672	
   673			damos_isolate_page(page, demote_list);
   674			put_page(page);
   675		}
   676		pte_unmap_unlock(mapped_pte, ptl);
   677		cond_resched();
   678	
   679		return 0;
   680	}
   681	

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