From: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Subject: mm: soft-dirty: keep soft-dirty bits over thp migration
Soft dirty bit is designed to keep tracked over page migration. This
patch makes it work in the same manner for thp migration too.
Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Signed-off-by: Zi Yan <zi.yan@xxxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Anshuman Khandual <khandual@xxxxxxxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: David Nellans <dnellans@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/pgtable.h | 17 +++++++++++++++
fs/proc/task_mmu.c | 23 ++++++++++++--------
include/asm-generic/pgtable.h | 34 ++++++++++++++++++++++++++++++-
include/linux/swapops.h | 2 +
mm/huge_memory.c | 27 +++++++++++++++++++++---
5 files changed, 90 insertions(+), 13 deletions(-)
diff -puN arch/x86/include/asm/pgtable.h~mm-soft-dirty-keep-soft-dirty-bits-over-thp-migration arch/x86/include/asm/pgtable.h
--- a/arch/x86/include/asm/pgtable.h~mm-soft-dirty-keep-soft-dirty-bits-over-thp-migration
+++ a/arch/x86/include/asm/pgtable.h
@@ -1172,6 +1172,23 @@ static inline pte_t pte_swp_clear_soft_d
{
return pte_clear_flags(pte, _PAGE_SWP_SOFT_DIRTY);
}
+
+#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
+static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
+{
+ return pmd_set_flags(pmd, _PAGE_SWP_SOFT_DIRTY);
+}
+
+static inline int pmd_swp_soft_dirty(pmd_t pmd)
+{
+ return pmd_flags(pmd) & _PAGE_SWP_SOFT_DIRTY;
+}
+
+static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
+{
+ return pmd_clear_flags(pmd, _PAGE_SWP_SOFT_DIRTY);
+}
+#endif
#endif
#define PKRU_AD_BIT 0x1
diff -puN fs/proc/task_mmu.c~mm-soft-dirty-keep-soft-dirty-bits-over-thp-migration fs/proc/task_mmu.c
--- a/fs/proc/task_mmu.c~mm-soft-dirty-keep-soft-dirty-bits-over-thp-migration
+++ a/fs/proc/task_mmu.c
@@ -978,17 +978,22 @@ static inline void clear_soft_dirty_pmd(
{
pmd_t pmd = *pmdp;
- /* See comment in change_huge_pmd() */
- pmdp_invalidate(vma, addr, pmdp);
- if (pmd_dirty(*pmdp))
- pmd = pmd_mkdirty(pmd);
- if (pmd_young(*pmdp))
- pmd = pmd_mkyoung(pmd);
+ if (pmd_present(pmd)) {
+ /* See comment in change_huge_pmd() */
+ pmdp_invalidate(vma, addr, pmdp);
+ if (pmd_dirty(*pmdp))
+ pmd = pmd_mkdirty(pmd);
+ if (pmd_young(*pmdp))
+ pmd = pmd_mkyoung(pmd);
- pmd = pmd_wrprotect(pmd);
- pmd = pmd_clear_soft_dirty(pmd);
+ pmd = pmd_wrprotect(pmd);
+ pmd = pmd_clear_soft_dirty(pmd);
- set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
+ set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
+ } else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
+ pmd = pmd_swp_clear_soft_dirty(pmd);
+ set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
+ }
}
#else
static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
diff -puN include/asm-generic/pgtable.h~mm-soft-dirty-keep-soft-dirty-bits-over-thp-migration include/asm-generic/pgtable.h
--- a/include/asm-generic/pgtable.h~mm-soft-dirty-keep-soft-dirty-bits-over-thp-migration
+++ a/include/asm-generic/pgtable.h
@@ -630,7 +630,24 @@ static inline void ptep_modify_prot_comm
#define arch_start_context_switch(prev) do {} while (0)
#endif
-#ifndef CONFIG_HAVE_ARCH_SOFT_DIRTY
+#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
+#ifndef CONFIG_ARCH_ENABLE_THP_MIGRATION
+static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
+{
+ return pmd;
+}
+
+static inline int pmd_swp_soft_dirty(pmd_t pmd)
+{
+ return 0;
+}
+
+static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
+{
+ return pmd;
+}
+#endif
+#else /* !CONFIG_HAVE_ARCH_SOFT_DIRTY */
static inline int pte_soft_dirty(pte_t pte)
{
return 0;
@@ -675,6 +692,21 @@ static inline pte_t pte_swp_clear_soft_d
{
return pte;
}
+
+static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
+{
+ return pmd;
+}
+
+static inline int pmd_swp_soft_dirty(pmd_t pmd)
+{
+ return 0;
+}
+
+static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
+{
+ return pmd;
+}
#endif
#ifndef __HAVE_PFNMAP_TRACKING
diff -puN include/linux/swapops.h~mm-soft-dirty-keep-soft-dirty-bits-over-thp-migration include/linux/swapops.h
--- a/include/linux/swapops.h~mm-soft-dirty-keep-soft-dirty-bits-over-thp-migration
+++ a/include/linux/swapops.h
@@ -183,6 +183,8 @@ static inline swp_entry_t pmd_to_swp_ent
{
swp_entry_t arch_entry;
+ if (pmd_swp_soft_dirty(pmd))
+ pmd = pmd_swp_clear_soft_dirty(pmd);
arch_entry = __pmd_to_swp_entry(pmd);
return swp_entry(__swp_type(arch_entry), __swp_offset(arch_entry));
}
diff -puN mm/huge_memory.c~mm-soft-dirty-keep-soft-dirty-bits-over-thp-migration mm/huge_memory.c
--- a/mm/huge_memory.c~mm-soft-dirty-keep-soft-dirty-bits-over-thp-migration
+++ a/mm/huge_memory.c
@@ -937,6 +937,8 @@ int copy_huge_pmd(struct mm_struct *dst_
if (is_write_migration_entry(entry)) {
make_migration_entry_read(&entry);
pmd = swp_entry_to_pmd(entry);
+ if (pmd_swp_soft_dirty(*src_pmd))
+ pmd = pmd_swp_mksoft_dirty(pmd);
set_pmd_at(src_mm, addr, src_pmd, pmd);
}
set_pmd_at(dst_mm, addr, dst_pmd, pmd);
@@ -1756,6 +1758,17 @@ static inline int pmd_move_must_withdraw
}
#endif
+static pmd_t move_soft_dirty_pmd(pmd_t pmd)
+{
+#ifdef CONFIG_MEM_SOFT_DIRTY
+ if (unlikely(is_pmd_migration_entry(pmd)))
+ pmd = pmd_swp_mksoft_dirty(pmd);
+ else if (pmd_present(pmd))
+ pmd = pmd_mksoft_dirty(pmd);
+#endif
+ return pmd;
+}
+
bool move_huge_pmd(struct vm_area_struct *vma, unsigned long old_addr,
unsigned long new_addr, unsigned long old_end,
pmd_t *old_pmd, pmd_t *new_pmd, bool *need_flush)
@@ -1798,7 +1811,8 @@ bool move_huge_pmd(struct vm_area_struct
pgtable = pgtable_trans_huge_withdraw(mm, old_pmd);
pgtable_trans_huge_deposit(mm, new_pmd, pgtable);
}
- set_pmd_at(mm, new_addr, new_pmd, pmd_mksoft_dirty(pmd));
+ pmd = move_soft_dirty_pmd(pmd);
+ set_pmd_at(mm, new_addr, new_pmd, pmd);
if (new_ptl != old_ptl)
spin_unlock(new_ptl);
if (force_flush)
@@ -1846,6 +1860,8 @@ int change_huge_pmd(struct vm_area_struc
*/
make_migration_entry_read(&entry);
newpmd = swp_entry_to_pmd(entry);
+ if (pmd_swp_soft_dirty(*pmd))
+ newpmd = pmd_swp_mksoft_dirty(newpmd);
set_pmd_at(mm, addr, pmd, newpmd);
}
goto unlock;
@@ -2824,6 +2840,7 @@ void set_pmd_migration_entry(struct page
unsigned long address = pvmw->address;
pmd_t pmdval;
swp_entry_t entry;
+ pmd_t pmdswp;
if (!(pvmw->pmd && !pvmw->pte))
return;
@@ -2837,8 +2854,10 @@ void set_pmd_migration_entry(struct page
if (pmd_dirty(pmdval))
set_page_dirty(page);
entry = make_migration_entry(page, pmd_write(pmdval));
- pmdval = swp_entry_to_pmd(entry);
- set_pmd_at(mm, address, pvmw->pmd, pmdval);
+ pmdswp = swp_entry_to_pmd(entry);
+ if (pmd_soft_dirty(pmdval))
+ pmdswp = pmd_swp_mksoft_dirty(pmdswp);
+ set_pmd_at(mm, address, pvmw->pmd, pmdswp);
page_remove_rmap(page, true);
put_page(page);
@@ -2861,6 +2880,8 @@ void remove_migration_pmd(struct page_vm
entry = pmd_to_swp_entry(*pvmw->pmd);
get_page(new);
pmde = pmd_mkold(mk_huge_pmd(new, vma->vm_page_prot));
+ if (pmd_swp_soft_dirty(*pvmw->pmd))
+ pmde = pmd_mksoft_dirty(pmde);
if (is_write_migration_entry(entry))
pmde = maybe_pmd_mkwrite(pmde, vma);
_
--
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