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Diffstat (limited to 'mm/rmap.c')
-rw-r--r--mm/rmap.c107
1 files changed, 45 insertions, 62 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index 1963e269314d..882a85826bb2 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -103,7 +103,7 @@ int anon_vma_prepare(struct vm_area_struct *vma)
spin_lock(&mm->page_table_lock);
if (likely(!vma->anon_vma)) {
vma->anon_vma = anon_vma;
- list_add(&vma->anon_vma_node, &anon_vma->head);
+ list_add_tail(&vma->anon_vma_node, &anon_vma->head);
allocated = NULL;
}
spin_unlock(&mm->page_table_lock);
@@ -127,7 +127,7 @@ void __anon_vma_link(struct vm_area_struct *vma)
struct anon_vma *anon_vma = vma->anon_vma;
if (anon_vma) {
- list_add(&vma->anon_vma_node, &anon_vma->head);
+ list_add_tail(&vma->anon_vma_node, &anon_vma->head);
validate_anon_vma(vma);
}
}
@@ -138,7 +138,7 @@ void anon_vma_link(struct vm_area_struct *vma)
if (anon_vma) {
spin_lock(&anon_vma->lock);
- list_add(&vma->anon_vma_node, &anon_vma->head);
+ list_add_tail(&vma->anon_vma_node, &anon_vma->head);
validate_anon_vma(vma);
spin_unlock(&anon_vma->lock);
}
@@ -205,44 +205,6 @@ out:
return anon_vma;
}
-#ifdef CONFIG_MIGRATION
-/*
- * Remove an anonymous page from swap replacing the swap pte's
- * through real pte's pointing to valid pages and then releasing
- * the page from the swap cache.
- *
- * Must hold page lock on page and mmap_sem of one vma that contains
- * the page.
- */
-void remove_from_swap(struct page *page)
-{
- struct anon_vma *anon_vma;
- struct vm_area_struct *vma;
- unsigned long mapping;
-
- if (!PageSwapCache(page))
- return;
-
- mapping = (unsigned long)page->mapping;
-
- if (!mapping || (mapping & PAGE_MAPPING_ANON) == 0)
- return;
-
- /*
- * We hold the mmap_sem lock. So no need to call page_lock_anon_vma.
- */
- anon_vma = (struct anon_vma *) (mapping - PAGE_MAPPING_ANON);
- spin_lock(&anon_vma->lock);
-
- list_for_each_entry(vma, &anon_vma->head, anon_vma_node)
- remove_vma_swap(vma, page);
-
- spin_unlock(&anon_vma->lock);
- delete_from_swap_cache(page);
-}
-EXPORT_SYMBOL(remove_from_swap);
-#endif
-
/*
* At what user virtual address is page expected in vma?
*/
@@ -578,7 +540,7 @@ void page_remove_rmap(struct page *page)
* repeatedly from either try_to_unmap_anon or try_to_unmap_file.
*/
static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
- int ignore_refs)
+ int migration)
{
struct mm_struct *mm = vma->vm_mm;
unsigned long address;
@@ -602,7 +564,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
*/
if ((vma->vm_flags & VM_LOCKED) ||
(ptep_clear_flush_young(vma, address, pte)
- && !ignore_refs)) {
+ && !migration)) {
ret = SWAP_FAIL;
goto out_unmap;
}
@@ -620,24 +582,45 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
if (PageAnon(page)) {
swp_entry_t entry = { .val = page_private(page) };
- /*
- * Store the swap location in the pte.
- * See handle_pte_fault() ...
- */
- BUG_ON(!PageSwapCache(page));
- swap_duplicate(entry);
- if (list_empty(&mm->mmlist)) {
- spin_lock(&mmlist_lock);
- if (list_empty(&mm->mmlist))
- list_add(&mm->mmlist, &init_mm.mmlist);
- spin_unlock(&mmlist_lock);
+
+ if (PageSwapCache(page)) {
+ /*
+ * Store the swap location in the pte.
+ * See handle_pte_fault() ...
+ */
+ swap_duplicate(entry);
+ if (list_empty(&mm->mmlist)) {
+ spin_lock(&mmlist_lock);
+ if (list_empty(&mm->mmlist))
+ list_add(&mm->mmlist, &init_mm.mmlist);
+ spin_unlock(&mmlist_lock);
+ }
+ dec_mm_counter(mm, anon_rss);
+#ifdef CONFIG_MIGRATION
+ } else {
+ /*
+ * Store the pfn of the page in a special migration
+ * pte. do_swap_page() will wait until the migration
+ * pte is removed and then restart fault handling.
+ */
+ BUG_ON(!migration);
+ entry = make_migration_entry(page, pte_write(pteval));
+#endif
}
set_pte_at(mm, address, pte, swp_entry_to_pte(entry));
BUG_ON(pte_file(*pte));
- dec_mm_counter(mm, anon_rss);
} else
+#ifdef CONFIG_MIGRATION
+ if (migration) {
+ /* Establish migration entry for a file page */
+ swp_entry_t entry;
+ entry = make_migration_entry(page, pte_write(pteval));
+ set_pte_at(mm, address, pte, swp_entry_to_pte(entry));
+ } else
+#endif
dec_mm_counter(mm, file_rss);
+
page_remove_rmap(page);
page_cache_release(page);
@@ -736,7 +719,7 @@ static void try_to_unmap_cluster(unsigned long cursor,
pte_unmap_unlock(pte - 1, ptl);
}
-static int try_to_unmap_anon(struct page *page, int ignore_refs)
+static int try_to_unmap_anon(struct page *page, int migration)
{
struct anon_vma *anon_vma;
struct vm_area_struct *vma;
@@ -747,7 +730,7 @@ static int try_to_unmap_anon(struct page *page, int ignore_refs)
return ret;
list_for_each_entry(vma, &anon_vma->head, anon_vma_node) {
- ret = try_to_unmap_one(page, vma, ignore_refs);
+ ret = try_to_unmap_one(page, vma, migration);
if (ret == SWAP_FAIL || !page_mapped(page))
break;
}
@@ -764,7 +747,7 @@ static int try_to_unmap_anon(struct page *page, int ignore_refs)
*
* This function is only called from try_to_unmap for object-based pages.
*/
-static int try_to_unmap_file(struct page *page, int ignore_refs)
+static int try_to_unmap_file(struct page *page, int migration)
{
struct address_space *mapping = page->mapping;
pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
@@ -778,7 +761,7 @@ static int try_to_unmap_file(struct page *page, int ignore_refs)
spin_lock(&mapping->i_mmap_lock);
vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
- ret = try_to_unmap_one(page, vma, ignore_refs);
+ ret = try_to_unmap_one(page, vma, migration);
if (ret == SWAP_FAIL || !page_mapped(page))
goto out;
}
@@ -863,16 +846,16 @@ out:
* SWAP_AGAIN - we missed a mapping, try again later
* SWAP_FAIL - the page is unswappable
*/
-int try_to_unmap(struct page *page, int ignore_refs)
+int try_to_unmap(struct page *page, int migration)
{
int ret;
BUG_ON(!PageLocked(page));
if (PageAnon(page))
- ret = try_to_unmap_anon(page, ignore_refs);
+ ret = try_to_unmap_anon(page, migration);
else
- ret = try_to_unmap_file(page, ignore_refs);
+ ret = try_to_unmap_file(page, migration);
if (!page_mapped(page))
ret = SWAP_SUCCESS;