From: Huang Ying <ying.hu...@intel.com>

Original code is only for PMD migration entry, it is revised to
support PMD swap mapping.

Signed-off-by: "Huang, Ying" <ying.hu...@intel.com>
Cc: "Kirill A. Shutemov" <kirill.shute...@linux.intel.com>
Cc: Andrea Arcangeli <aarca...@redhat.com>
Cc: Michal Hocko <mho...@suse.com>
Cc: Johannes Weiner <han...@cmpxchg.org>
Cc: Shaohua Li <s...@kernel.org>
Cc: Hugh Dickins <hu...@google.com>
Cc: Minchan Kim <minc...@kernel.org>
Cc: Rik van Riel <r...@redhat.com>
Cc: Dave Hansen <dave.han...@linux.intel.com>
Cc: Naoya Horiguchi <n-horigu...@ah.jp.nec.com>
Cc: Zi Yan <zi....@cs.rutgers.edu>
---
 fs/proc/task_mmu.c |  8 ++++----
 mm/gup.c           | 22 ++++++++++++++++------
 mm/huge_memory.c   |  6 +++---
 mm/mempolicy.c     |  2 +-
 4 files changed, 24 insertions(+), 14 deletions(-)

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index c486ad4b43f0..a117a928ff9e 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -977,7 +977,7 @@ static inline void clear_soft_dirty_pmd(struct 
vm_area_struct *vma,
                pmd = pmd_clear_soft_dirty(pmd);
 
                set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
-       } else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
+       } else if (is_swap_pmd(pmd)) {
                pmd = pmd_swp_clear_soft_dirty(pmd);
                set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
        }
@@ -1307,7 +1307,7 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long 
addr, unsigned long end,
                                frame = pmd_pfn(pmd) +
                                        ((addr & ~PMD_MASK) >> PAGE_SHIFT);
                }
-#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
+#if defined(CONFIG_ARCH_ENABLE_THP_MIGRATION) || defined(CONFIG_THP_SWAP)
                else if (is_swap_pmd(pmd)) {
                        swp_entry_t entry = pmd_to_swp_entry(pmd);
                        unsigned long offset = swp_offset(entry);
@@ -1318,8 +1318,8 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long 
addr, unsigned long end,
                        flags |= PM_SWAP;
                        if (pmd_swp_soft_dirty(pmd))
                                flags |= PM_SOFT_DIRTY;
-                       VM_BUG_ON(!is_pmd_migration_entry(pmd));
-                       page = migration_entry_to_page(entry);
+                       if (is_pmd_migration_entry(pmd))
+                               page = migration_entry_to_page(entry);
                }
 #endif
 
diff --git a/mm/gup.c b/mm/gup.c
index 76af4cfeaf68..03e738687528 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -216,6 +216,7 @@ static struct page *follow_pmd_mask(struct vm_area_struct 
*vma,
        spinlock_t *ptl;
        struct page *page;
        struct mm_struct *mm = vma->vm_mm;
+       swp_entry_t entry;
 
        pmd = pmd_offset(pudp, address);
        if (pmd_none(*pmd))
@@ -238,11 +239,14 @@ static struct page *follow_pmd_mask(struct vm_area_struct 
*vma,
        if (!pmd_present(*pmd)) {
                if (likely(!(flags & FOLL_MIGRATION)))
                        return no_page_table(vma, flags);
-               VM_BUG_ON(thp_migration_supported() &&
-                                 !is_pmd_migration_entry(*pmd));
-               if (is_pmd_migration_entry(*pmd))
+               entry = pmd_to_swp_entry(*pmd);
+               if (thp_migration_supported() && is_migration_entry(entry)) {
                        pmd_migration_entry_wait(mm, pmd);
-               goto retry;
+                       goto retry;
+               }
+               if (thp_swap_supported() && !non_swap_entry(entry))
+                       return no_page_table(vma, flags);
+               VM_BUG_ON(1);
        }
        if (pmd_devmap(*pmd)) {
                ptl = pmd_lock(mm, pmd);
@@ -260,11 +264,17 @@ static struct page *follow_pmd_mask(struct vm_area_struct 
*vma,
 retry_locked:
        ptl = pmd_lock(mm, pmd);
        if (unlikely(!pmd_present(*pmd))) {
+               entry = pmd_to_swp_entry(*pmd);
                spin_unlock(ptl);
                if (likely(!(flags & FOLL_MIGRATION)))
                        return no_page_table(vma, flags);
-               pmd_migration_entry_wait(mm, pmd);
-               goto retry_locked;
+               if (thp_migration_supported() && is_migration_entry(entry)) {
+                       pmd_migration_entry_wait(mm, pmd);
+                       goto retry_locked;
+               }
+               if (thp_swap_supported() && !non_swap_entry(entry))
+                       return no_page_table(vma, flags);
+               VM_BUG_ON(1);
        }
        if (unlikely(!pmd_trans_huge(*pmd))) {
                spin_unlock(ptl);
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 3490f1baea49..51cc71ef4b83 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2078,7 +2078,7 @@ static inline int pmd_move_must_withdraw(spinlock_t 
*new_pmd_ptl,
 static pmd_t move_soft_dirty_pmd(pmd_t pmd)
 {
 #ifdef CONFIG_MEM_SOFT_DIRTY
-       if (unlikely(is_pmd_migration_entry(pmd)))
+       if (unlikely(is_swap_pmd(pmd)))
                pmd = pmd_swp_mksoft_dirty(pmd);
        else if (pmd_present(pmd))
                pmd = pmd_mksoft_dirty(pmd);
@@ -2164,11 +2164,11 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t 
*pmd,
        preserve_write = prot_numa && pmd_write(*pmd);
        ret = 1;
 
-#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
+#if defined(CONFIG_ARCH_ENABLE_THP_MIGRATION) || defined(CONFIG_THP_SWAP)
        if (is_swap_pmd(*pmd)) {
                swp_entry_t entry = pmd_to_swp_entry(*pmd);
 
-               VM_BUG_ON(!is_pmd_migration_entry(*pmd));
+               VM_BUG_ON(!thp_swap_supported() && !is_migration_entry(entry));
                if (is_write_migration_entry(entry)) {
                        pmd_t newpmd;
                        /*
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 9ac49ef17b4e..180d7c08f6cc 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -436,7 +436,7 @@ static int queue_pages_pmd(pmd_t *pmd, spinlock_t *ptl, 
unsigned long addr,
        struct queue_pages *qp = walk->private;
        unsigned long flags;
 
-       if (unlikely(is_pmd_migration_entry(*pmd))) {
+       if (unlikely(is_swap_pmd(*pmd))) {
                ret = 1;
                goto unlock;
        }
-- 
2.17.0

Reply via email to