mm/hmm/mirror: helper to snapshot CPU page table

[sfrench/cifs-2.6.git] / mm / migrate.c

diff --git a/mm/migrate.c b/mm/migrate.c
index e84eeb4e43566c7b1ee85e3759b1b60b72c1c532..1088cef6ef8be0f0cd90ce476527abbaa631d9ab 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -185,8 +185,8 @@ void putback_movable_pages(struct list_head *l)
                        unlock_page(page);
                        put_page(page);
                } else {
-                       dec_node_page_state(page, NR_ISOLATED_ANON +
-                                       page_is_file_cache(page));
+                       mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON +
+                                       page_is_file_cache(page), -hpage_nr_pages(page));
                        putback_lru_page(page);
                }
        }
@@ -216,6 +216,15 @@ static bool remove_migration_pte(struct page *page, struct vm_area_struct *vma,
                        new = page - pvmw.page->index +
                                linear_page_index(vma, pvmw.address);
 
+#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
+               /* PMD-mapped THP migration entry */
+               if (!pvmw.pte) {
+                       VM_BUG_ON_PAGE(PageHuge(page) || !PageTransCompound(page), page);
+                       remove_migration_pmd(&pvmw, new);
+                       continue;
+               }
+#endif
+
                get_page(new);
                pte = pte_mkold(mk_pte(new, READ_ONCE(vma->vm_page_prot)));
                if (pte_swp_soft_dirty(*pvmw.pte))
@@ -330,6 +339,27 @@ void migration_entry_wait_huge(struct vm_area_struct *vma,
        __migration_entry_wait(mm, pte, ptl);
 }
 
+#ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION
+void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd)
+{
+       spinlock_t *ptl;
+       struct page *page;
+
+       ptl = pmd_lock(mm, pmd);
+       if (!is_pmd_migration_entry(*pmd))
+               goto unlock;
+       page = migration_entry_to_page(pmd_to_swp_entry(*pmd));
+       if (!get_page_unless_zero(page))
+               goto unlock;
+       spin_unlock(ptl);
+       wait_on_page_locked(page);
+       put_page(page);
+       return;
+unlock:
+       spin_unlock(ptl);
+}
+#endif
+
 #ifdef CONFIG_BLOCK
 /* Returns true if all buffers are successfully locked */
 static bool buffer_migrate_lock_buffers(struct buffer_head *head,
@@ -1088,7 +1118,7 @@ static ICE_noinline int unmap_and_move(new_page_t get_new_page,
                goto out;
        }
 
-       if (unlikely(PageTransHuge(page))) {
+       if (unlikely(PageTransHuge(page) && !PageTransHuge(newpage))) {
                lock_page(page);
                rc = split_huge_page(page);
                unlock_page(page);
@@ -1116,8 +1146,8 @@ out:
                 * as __PageMovable
                 */
                if (likely(!__PageMovable(page)))
-                       dec_node_page_state(page, NR_ISOLATED_ANON +
-                                       page_is_file_cache(page));
+                       mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON +
+                                       page_is_file_cache(page), -hpage_nr_pages(page));
        }
 
        /*
@@ -1391,7 +1421,17 @@ static struct page *new_page_node(struct page *p, unsigned long private,
        if (PageHuge(p))
                return alloc_huge_page_node(page_hstate(compound_head(p)),
                                        pm->node);
-       else
+       else if (thp_migration_supported() && PageTransHuge(p)) {
+               struct page *thp;
+
+               thp = alloc_pages_node(pm->node,
+                       (GFP_TRANSHUGE | __GFP_THISNODE) & ~__GFP_RECLAIM,
+                       HPAGE_PMD_ORDER);
+               if (!thp)
+                       return NULL;
+               prep_transhuge_page(thp);
+               return thp;
+       } else
                return __alloc_pages_node(pm->node,
                                GFP_HIGHUSER_MOVABLE | __GFP_THISNODE, 0);
 }
@@ -1418,6 +1458,8 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
        for (pp = pm; pp->node != MAX_NUMNODES; pp++) {
                struct vm_area_struct *vma;
                struct page *page;
+               struct page *head;
+               unsigned int follflags;
 
                err = -EFAULT;
                vma = find_vma(mm, pp->addr);
@@ -1425,8 +1467,10 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
                        goto set_status;
 
                /* FOLL_DUMP to ignore special (like zero) pages */
-               page = follow_page(vma, pp->addr,
-                               FOLL_GET | FOLL_SPLIT | FOLL_DUMP);
+               follflags = FOLL_GET | FOLL_DUMP;
+               if (!thp_migration_supported())
+                       follflags |= FOLL_SPLIT;
+               page = follow_page(vma, pp->addr, follflags);
 
                err = PTR_ERR(page);
                if (IS_ERR(page))
@@ -1436,7 +1480,6 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
                if (!page)
                        goto set_status;
 
-               pp->page = page;
                err = page_to_nid(page);
 
                if (err == pp->node)
@@ -1451,16 +1494,22 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
                        goto put_and_set;
 
                if (PageHuge(page)) {
-                       if (PageHead(page))
+                       if (PageHead(page)) {
                                isolate_huge_page(page, &pagelist);
+                               err = 0;
+                               pp->page = page;
+                       }
                        goto put_and_set;
                }
 
-               err = isolate_lru_page(page);
+               pp->page = compound_head(page);
+               head = compound_head(page);
+               err = isolate_lru_page(head);
                if (!err) {
-                       list_add_tail(&page->lru, &pagelist);
-                       inc_node_page_state(page, NR_ISOLATED_ANON +
-                                           page_is_file_cache(page));
+                       list_add_tail(&head->lru, &pagelist);
+                       mod_node_page_state(page_pgdat(head),
+                               NR_ISOLATED_ANON + page_is_file_cache(head),
+                               hpage_nr_pages(head));
                }
 put_and_set:
                /*