diff options
Diffstat (limited to 'include/asm-generic/pgtable.h')
| -rw-r--r-- | include/asm-generic/pgtable.h | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 4d7bb98f4134..4f93a6d10a47 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -846,7 +846,23 @@ static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t *pmd) #ifdef CONFIG_TRANSPARENT_HUGEPAGE barrier(); #endif - if (pmd_none(pmdval) || pmd_trans_huge(pmdval)) + /* + * !pmd_present() checks for pmd migration entries + * + * The complete check uses is_pmd_migration_entry() in linux/swapops.h + * But using that requires moving current function and pmd_trans_unstable() + * to linux/swapops.h to resovle dependency, which is too much code move. + * + * !pmd_present() is equivalent to is_pmd_migration_entry() currently, + * because !pmd_present() pages can only be under migration not swapped + * out. + * + * pmd_none() is preseved for future condition checks on pmd migration + * entries and not confusing with this function name, although it is + * redundant with !pmd_present(). + */ + if (pmd_none(pmdval) || pmd_trans_huge(pmdval) || + (IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION) && !pmd_present(pmdval))) return 1; if (unlikely(pmd_bad(pmdval))) { pmd_clear_bad(pmd); |