X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=mm%2Frmap.c;h=b3263cb323616febd5a83d13d0ea2595fe2f62f8;hb=52629506420ce32997f1fba0a1ab2f1aaa9a4f79;hp=068522d8502a58e9465a963e68c37ce4ccf635d7;hpb=ef350bb7c5e0748f7d17f1d70c6b0eec5f64f446;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git

diff --git a/mm/rmap.c b/mm/rmap.c
index 068522d..b3263cb 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1179,15 +1179,18 @@ out:
 /*
  * Subfunctions of try_to_unmap: try_to_unmap_one called
  * repeatedly from try_to_unmap_ksm, try_to_unmap_anon or try_to_unmap_file.
+ *
+ * @arg: enum ttu_flags will be passed to this argument
  */
 int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
-		     unsigned long address, enum ttu_flags flags)
+		     unsigned long address, void *arg)
 {
 	struct mm_struct *mm = vma->vm_mm;
 	pte_t *pte;
 	pte_t pteval;
 	spinlock_t *ptl;
 	int ret = SWAP_AGAIN;
+	enum ttu_flags flags = (enum ttu_flags)arg;
 
 	pte = page_check_address(page, mm, address, &ptl, 0);
 	if (!pte)
@@ -1426,6 +1429,79 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
 	return ret;
 }
 
+static int try_to_unmap_nonlinear(struct page *page,
+		struct address_space *mapping, struct vm_area_struct *vma)
+{
+	int ret = SWAP_AGAIN;
+	unsigned long cursor;
+	unsigned long max_nl_cursor = 0;
+	unsigned long max_nl_size = 0;
+	unsigned int mapcount;
+
+	list_for_each_entry(vma,
+		&mapping->i_mmap_nonlinear, shared.nonlinear) {
+
+		cursor = (unsigned long) vma->vm_private_data;
+		if (cursor > max_nl_cursor)
+			max_nl_cursor = cursor;
+		cursor = vma->vm_end - vma->vm_start;
+		if (cursor > max_nl_size)
+			max_nl_size = cursor;
+	}
+
+	if (max_nl_size == 0) {	/* all nonlinears locked or reserved ? */
+		return SWAP_FAIL;
+	}
+
+	/*
+	 * We don't try to search for this page in the nonlinear vmas,
+	 * and page_referenced wouldn't have found it anyway.  Instead
+	 * just walk the nonlinear vmas trying to age and unmap some.
+	 * The mapcount of the page we came in with is irrelevant,
+	 * but even so use it as a guide to how hard we should try?
+	 */
+	mapcount = page_mapcount(page);
+	if (!mapcount)
+		return ret;
+
+	cond_resched();
+
+	max_nl_size = (max_nl_size + CLUSTER_SIZE - 1) & CLUSTER_MASK;
+	if (max_nl_cursor == 0)
+		max_nl_cursor = CLUSTER_SIZE;
+
+	do {
+		list_for_each_entry(vma,
+			&mapping->i_mmap_nonlinear, shared.nonlinear) {
+
+			cursor = (unsigned long) vma->vm_private_data;
+			while (cursor < max_nl_cursor &&
+				cursor < vma->vm_end - vma->vm_start) {
+				if (try_to_unmap_cluster(cursor, &mapcount,
+						vma, page) == SWAP_MLOCK)
+					ret = SWAP_MLOCK;
+				cursor += CLUSTER_SIZE;
+				vma->vm_private_data = (void *) cursor;
+				if ((int)mapcount <= 0)
+					return ret;
+			}
+			vma->vm_private_data = (void *) max_nl_cursor;
+		}
+		cond_resched();
+		max_nl_cursor += CLUSTER_SIZE;
+	} while (max_nl_cursor <= max_nl_size);
+
+	/*
+	 * Don't loop forever (perhaps all the remaining pages are
+	 * in locked vmas).  Reset cursor on all unreserved nonlinear
+	 * vmas, now forgetting on which ones it had fallen behind.
+	 */
+	list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.nonlinear)
+		vma->vm_private_data = NULL;
+
+	return ret;
+}
+
 bool is_vma_temporary_stack(struct vm_area_struct *vma)
 {
 	int maybe_stack = vma->vm_flags & (VM_GROWSDOWN | VM_GROWSUP);
@@ -1440,6 +1516,11 @@ bool is_vma_temporary_stack(struct vm_area_struct *vma)
 	return false;
 }
 
+static bool invalid_migration_vma(struct vm_area_struct *vma, void *arg)
+{
+	return is_vma_temporary_stack(vma);
+}
+
 /**
  * try_to_unmap_anon - unmap or unlock anonymous page using the object-based
  * rmap method
@@ -1485,7 +1566,7 @@ static int try_to_unmap_anon(struct page *page, enum ttu_flags flags)
 			continue;
 
 		address = vma_address(page, vma);
-		ret = try_to_unmap_one(page, vma, address, flags);
+		ret = try_to_unmap_one(page, vma, address, (void *)flags);
 		if (ret != SWAP_AGAIN || !page_mapped(page))
 			break;
 	}
@@ -1512,21 +1593,14 @@ static int try_to_unmap_anon(struct page *page, enum ttu_flags flags)
 static int try_to_unmap_file(struct page *page, enum ttu_flags flags)
 {
 	struct address_space *mapping = page->mapping;
-	pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+	pgoff_t pgoff = page->index << compound_order(page);
 	struct vm_area_struct *vma;
 	int ret = SWAP_AGAIN;
-	unsigned long cursor;
-	unsigned long max_nl_cursor = 0;
-	unsigned long max_nl_size = 0;
-	unsigned int mapcount;
-
-	if (PageHuge(page))
-		pgoff = page->index << compound_order(page);
 
 	mutex_lock(&mapping->i_mmap_mutex);
 	vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
 		unsigned long address = vma_address(page, vma);
-		ret = try_to_unmap_one(page, vma, address, flags);
+		ret = try_to_unmap_one(page, vma, address, (void *)flags);
 		if (ret != SWAP_AGAIN || !page_mapped(page))
 			goto out;
 	}
@@ -1542,69 +1616,17 @@ static int try_to_unmap_file(struct page *page, enum ttu_flags flags)
 	if (TTU_ACTION(flags) == TTU_MUNLOCK)
 		goto out;
 
-	list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
-							shared.nonlinear) {
-		cursor = (unsigned long) vma->vm_private_data;
-		if (cursor > max_nl_cursor)
-			max_nl_cursor = cursor;
-		cursor = vma->vm_end - vma->vm_start;
-		if (cursor > max_nl_size)
-			max_nl_size = cursor;
-	}
-
-	if (max_nl_size == 0) {	/* all nonlinears locked or reserved ? */
-		ret = SWAP_FAIL;
-		goto out;
-	}
-
-	/*
-	 * We don't try to search for this page in the nonlinear vmas,
-	 * and page_referenced wouldn't have found it anyway.  Instead
-	 * just walk the nonlinear vmas trying to age and unmap some.
-	 * The mapcount of the page we came in with is irrelevant,
-	 * but even so use it as a guide to how hard we should try?
-	 */
-	mapcount = page_mapcount(page);
-	if (!mapcount)
-		goto out;
-	cond_resched();
-
-	max_nl_size = (max_nl_size + CLUSTER_SIZE - 1) & CLUSTER_MASK;
-	if (max_nl_cursor == 0)
-		max_nl_cursor = CLUSTER_SIZE;
-
-	do {
-		list_for_each_entry(vma, &mapping->i_mmap_nonlinear,
-							shared.nonlinear) {
-			cursor = (unsigned long) vma->vm_private_data;
-			while ( cursor < max_nl_cursor &&
-				cursor < vma->vm_end - vma->vm_start) {
-				if (try_to_unmap_cluster(cursor, &mapcount,
-						vma, page) == SWAP_MLOCK)
-					ret = SWAP_MLOCK;
-				cursor += CLUSTER_SIZE;
-				vma->vm_private_data = (void *) cursor;
-				if ((int)mapcount <= 0)
-					goto out;
-			}
-			vma->vm_private_data = (void *) max_nl_cursor;
-		}
-		cond_resched();
-		max_nl_cursor += CLUSTER_SIZE;
-	} while (max_nl_cursor <= max_nl_size);
-
-	/*
-	 * Don't loop forever (perhaps all the remaining pages are
-	 * in locked vmas).  Reset cursor on all unreserved nonlinear
-	 * vmas, now forgetting on which ones it had fallen behind.
-	 */
-	list_for_each_entry(vma, &mapping->i_mmap_nonlinear, shared.nonlinear)
-		vma->vm_private_data = NULL;
+	ret = try_to_unmap_nonlinear(page, mapping, vma);
 out:
 	mutex_unlock(&mapping->i_mmap_mutex);
 	return ret;
 }
 
+static int page_not_mapped(struct page *page)
+{
+	return !page_mapped(page);
+};
+
 /**
  * try_to_unmap - try to remove all page table mappings to a page
  * @page: the page to get unmapped
@@ -1622,16 +1644,29 @@ out:
 int try_to_unmap(struct page *page, enum ttu_flags flags)
 {
 	int ret;
+	struct rmap_walk_control rwc = {
+		.rmap_one = try_to_unmap_one,
+		.arg = (void *)flags,
+		.done = page_not_mapped,
+		.file_nonlinear = try_to_unmap_nonlinear,
+		.anon_lock = page_lock_anon_vma_read,
+	};
 
-	BUG_ON(!PageLocked(page));
 	VM_BUG_ON(!PageHuge(page) && PageTransHuge(page));
 
-	if (unlikely(PageKsm(page)))
-		ret = try_to_unmap_ksm(page, flags);
-	else if (PageAnon(page))
-		ret = try_to_unmap_anon(page, flags);
-	else
-		ret = try_to_unmap_file(page, flags);
+	/*
+	 * During exec, a temporary VMA is setup and later moved.
+	 * The VMA is moved under the anon_vma lock but not the
+	 * page tables leading to a race where migration cannot
+	 * find the migration ptes. Rather than increasing the
+	 * locking requirements of exec(), migration skips
+	 * temporary VMAs until after exec() completes.
+	 */
+	if (flags & TTU_MIGRATION && !PageKsm(page) && PageAnon(page))
+		rwc.invalid_vma = invalid_migration_vma;
+
+	ret = rmap_walk(page, &rwc);
+
 	if (ret != SWAP_MLOCK && !page_mapped(page))
 		ret = SWAP_SUCCESS;
 	return ret;
@@ -1674,18 +1709,13 @@ void __put_anon_vma(struct anon_vma *anon_vma)
 	anon_vma_free(anon_vma);
 }
 
-#ifdef CONFIG_MIGRATION
-/*
- * rmap_walk() and its helpers rmap_walk_anon() and rmap_walk_file():
- * Called by migrate.c to remove migration ptes, but might be used more later.
- */
-static int rmap_walk_anon(struct page *page, int (*rmap_one)(struct page *,
-		struct vm_area_struct *, unsigned long, void *), void *arg)
+static struct anon_vma *rmap_walk_anon_lock(struct page *page,
+					struct rmap_walk_control *rwc)
 {
 	struct anon_vma *anon_vma;
-	pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
-	struct anon_vma_chain *avc;
-	int ret = SWAP_AGAIN;
+
+	if (rwc->anon_lock)
+		return rwc->anon_lock(page);
 
 	/*
 	 * Note: remove_migration_ptes() cannot use page_lock_anon_vma_read()
@@ -1695,24 +1725,48 @@ static int rmap_walk_anon(struct page *page, int (*rmap_one)(struct page *,
 	 */
 	anon_vma = page_anon_vma(page);
 	if (!anon_vma)
-		return ret;
+		return NULL;
+
 	anon_vma_lock_read(anon_vma);
+	return anon_vma;
+}
+
+/*
+ * rmap_walk() and its helpers rmap_walk_anon() and rmap_walk_file():
+ * Called by migrate.c to remove migration ptes, but might be used more later.
+ */
+static int rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc)
+{
+	struct anon_vma *anon_vma;
+	pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+	struct anon_vma_chain *avc;
+	int ret = SWAP_AGAIN;
+
+	anon_vma = rmap_walk_anon_lock(page, rwc);
+	if (!anon_vma)
+		return ret;
+
 	anon_vma_interval_tree_foreach(avc, &anon_vma->rb_root, pgoff, pgoff) {
 		struct vm_area_struct *vma = avc->vma;
 		unsigned long address = vma_address(page, vma);
-		ret = rmap_one(page, vma, address, arg);
+
+		if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg))
+			continue;
+
+		ret = rwc->rmap_one(page, vma, address, rwc->arg);
 		if (ret != SWAP_AGAIN)
 			break;
+		if (rwc->done && rwc->done(page))
+			break;
 	}
 	anon_vma_unlock_read(anon_vma);
 	return ret;
 }
 
-static int rmap_walk_file(struct page *page, int (*rmap_one)(struct page *,
-		struct vm_area_struct *, unsigned long, void *), void *arg)
+static int rmap_walk_file(struct page *page, struct rmap_walk_control *rwc)
 {
 	struct address_space *mapping = page->mapping;
-	pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+	pgoff_t pgoff = page->index << compound_order(page);
 	struct vm_area_struct *vma;
 	int ret = SWAP_AGAIN;
 
@@ -1721,32 +1775,41 @@ static int rmap_walk_file(struct page *page, int (*rmap_one)(struct page *,
 	mutex_lock(&mapping->i_mmap_mutex);
 	vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff, pgoff) {
 		unsigned long address = vma_address(page, vma);
-		ret = rmap_one(page, vma, address, arg);
+
+		if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg))
+			continue;
+
+		ret = rwc->rmap_one(page, vma, address, rwc->arg);
 		if (ret != SWAP_AGAIN)
-			break;
+			goto done;
+		if (rwc->done && rwc->done(page))
+			goto done;
 	}
-	/*
-	 * No nonlinear handling: being always shared, nonlinear vmas
-	 * never contain migration ptes.  Decide what to do about this
-	 * limitation to linear when we need rmap_walk() on nonlinear.
-	 */
+
+	if (!rwc->file_nonlinear)
+		goto done;
+
+	if (list_empty(&mapping->i_mmap_nonlinear))
+		goto done;
+
+	ret = rwc->file_nonlinear(page, mapping, vma);
+
+done:
 	mutex_unlock(&mapping->i_mmap_mutex);
 	return ret;
 }
 
-int rmap_walk(struct page *page, int (*rmap_one)(struct page *,
-		struct vm_area_struct *, unsigned long, void *), void *arg)
+int rmap_walk(struct page *page, struct rmap_walk_control *rwc)
 {
 	VM_BUG_ON(!PageLocked(page));
 
 	if (unlikely(PageKsm(page)))
-		return rmap_walk_ksm(page, rmap_one, arg);
+		return rmap_walk_ksm(page, rwc);
 	else if (PageAnon(page))
-		return rmap_walk_anon(page, rmap_one, arg);
+		return rmap_walk_anon(page, rwc);
 	else
-		return rmap_walk_file(page, rmap_one, arg);
+		return rmap_walk_file(page, rwc);
 }
-#endif /* CONFIG_MIGRATION */
 
 #ifdef CONFIG_HUGETLB_PAGE
 /*