Re: [PATCH 2/2] mm/MADV_COLLAPSE: catch !none !huge !bad pmd lookups

kernel test robot
2023-01-25T13:39:37Z

Hi Zach,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on akpm-mm/mm-everything]

url: https://github.com/intel-lab-lkp/linux/commits/Zach-O-Keefe/mm-MADV_COLLAPSE-catch-none-huge-bad-pmd-lookups/20230125-095954
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/20230125015738.912924-2-zokeefe%40google.com
patch subject: [PATCH 2/2] mm/MADV_COLLAPSE: catch !none !huge !bad pmd lookups
config: x86_64-rhel-8.3-kselftests (https://download.01.org/0day-ci/archive/20230125/202301252110.hFYRsbrm-lkp@intel.com/config)
compiler: gcc-11 (Debian 11.3.0-8) 11.3.0
reproduce (this is a W=1 build):
# https://github.com/intel-lab-lkp/linux/commit/6001eb9a8f1687a1d0b72831d991886106cac37b
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Zach-O-Keefe/mm-MADV_COLLAPSE-catch-none-huge-bad-pmd-lookups/20230125-095954
git checkout 6001eb9a8f1687a1d0b72831d991886106cac37b
# save the config file
mkdir build_dir && cp config build_dir/.config
make W=1 O=build_dir ARCH=x86_64 olddefconfig
make W=1 O=build_dir ARCH=x86_64 SHELL=/bin/bash

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

All errors (new ones prefixed by >>):

mm/khugepaged.c: In function 'find_pmd_or_thp_or_none':
>> mm/khugepaged.c:972:24: error: incompatible type for argument 1 of 'pmd_devmap'
972 | if (pmd_devmap(pmd))
| ^~~
| |
| pmd_t **
In file included from include/linux/pgtable.h:6,
from include/linux/mm.h:29,
from mm/khugepaged.c:4:
arch/x86/include/asm/pgtable.h:254:36: note: expected 'pmd_t' but argument is of type 'pmd_t **'
254 | static inline int pmd_devmap(pmd_t pmd)
| ~~~~~~^~~

vim +/pmd_devmap +972 mm/khugepaged.c

945
946 /*
947 * See pmd_trans_unstable() for how the result may change out from
948 * underneath us, even if we hold mmap_lock in read.
949 */
950 static int find_pmd_or_thp_or_none(struct mm_struct *mm,
951 unsigned long address,
952 pmd_t **pmd)
953 {
954 pmd_t pmde;
955
956 *pmd = mm_find_pmd(mm, address);
957 if (!*pmd)
958 return SCAN_PMD_NULL;
959
960 pmde = pmdp_get_lockless(*pmd);
961
962 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
963 /* See comments in pmd_none_or_trans_huge_or_clear_bad() */
964 barrier();
965 #endif
966 if (pmd_none(pmde))
967 return SCAN_PMD_NONE;
968 if (!pmd_present(pmde))
969 return SCAN_PMD_NULL;
970 if (pmd_trans_huge(pmde))
971 return SCAN_PMD_MAPPED;
> 972 if (pmd_devmap(pmd))
973 return SCAN_PMD_NULL;
974 if (pmd_bad(pmde))
975 return SCAN_PMD_NULL;
976 return SCAN_SUCCEED;
977 }
978

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