[PATCH -mm -v4 01/21] mm, THP, swap: Enable PMD swap operations for CONFIG_THP_SWAP

From: Huang, Ying
Date: Thu Jun 21 2018 - 23:55:18 EST


From: Huang Ying <ying.huang@xxxxxxxxx>

Previously, the PMD swap operations are only enabled for
CONFIG_ARCH_ENABLE_THP_MIGRATION. Because they are only used by the
THP migration support. We will support PMD swap mapping to the huge
swap cluster and swapin the THP as a whole. That will be enabled via
CONFIG_THP_SWAP and needs these PMD swap operations. So enable the
PMD swap operations for CONFIG_THP_SWAP too.

Signed-off-by: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Shaohua Li <shli@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Cc: Zi Yan <zi.yan@xxxxxxxxxxxxxx>
Cc: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
---
arch/x86/include/asm/pgtable.h | 2 +-
include/asm-generic/pgtable.h | 2 +-
include/linux/swapops.h | 44 ++++++++++++++++++++++--------------------
3 files changed, 25 insertions(+), 23 deletions(-)

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 99ecde23c3ec..13bf58838daf 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1224,7 +1224,7 @@ static inline pte_t pte_swp_clear_soft_dirty(pte_t pte)
return pte_clear_flags(pte, _PAGE_SWP_SOFT_DIRTY);
}

-#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
+#if defined(CONFIG_ARCH_ENABLE_THP_MIGRATION) || defined(CONFIG_THP_SWAP)
static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
{
return pmd_set_flags(pmd, _PAGE_SWP_SOFT_DIRTY);
diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h
index f59639afaa39..bb8354981a36 100644
--- a/include/asm-generic/pgtable.h
+++ b/include/asm-generic/pgtable.h
@@ -675,7 +675,7 @@ static inline void ptep_modify_prot_commit(struct mm_struct *mm,
#endif

#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
-#ifndef CONFIG_ARCH_ENABLE_THP_MIGRATION
+#if !defined(CONFIG_ARCH_ENABLE_THP_MIGRATION) && !defined(CONFIG_THP_SWAP)
static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
{
return pmd;
diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index 1d3877c39a00..f1be5a52f5c8 100644
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -258,17 +258,7 @@ static inline int is_write_migration_entry(swp_entry_t entry)

#endif

-struct page_vma_mapped_walk;
-
-#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
-extern void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw,
- struct page *page);
-
-extern void remove_migration_pmd(struct page_vma_mapped_walk *pvmw,
- struct page *new);
-
-extern void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd);
-
+#if defined(CONFIG_ARCH_ENABLE_THP_MIGRATION) || defined(CONFIG_THP_SWAP)
static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd)
{
swp_entry_t arch_entry;
@@ -286,6 +276,28 @@ static inline pmd_t swp_entry_to_pmd(swp_entry_t entry)
arch_entry = __swp_entry(swp_type(entry), swp_offset(entry));
return __swp_entry_to_pmd(arch_entry);
}
+#else
+static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd)
+{
+ return swp_entry(0, 0);
+}
+
+static inline pmd_t swp_entry_to_pmd(swp_entry_t entry)
+{
+ return __pmd(0);
+}
+#endif
+
+struct page_vma_mapped_walk;
+
+#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
+extern void set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw,
+ struct page *page);
+
+extern void remove_migration_pmd(struct page_vma_mapped_walk *pvmw,
+ struct page *new);
+
+extern void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd);

static inline int is_pmd_migration_entry(pmd_t pmd)
{
@@ -306,16 +318,6 @@ static inline void remove_migration_pmd(struct page_vma_mapped_walk *pvmw,

static inline void pmd_migration_entry_wait(struct mm_struct *m, pmd_t *p) { }

-static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd)
-{
- return swp_entry(0, 0);
-}
-
-static inline pmd_t swp_entry_to_pmd(swp_entry_t entry)
-{
- return __pmd(0);
-}
-
static inline int is_pmd_migration_entry(pmd_t pmd)
{
return 0;
--
2.16.4