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-rw-r--r--mm/migrate.c56
1 files changed, 40 insertions, 16 deletions
diff --git a/mm/migrate.c b/mm/migrate.c
index 13f47fbe3550..3acac4a62c4b 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -941,8 +941,9 @@ out:
* Obtain the lock on page, remove all ptes and migrate the page
* to the newly allocated page in newpage.
*/
-static int unmap_and_move(new_page_t get_new_page, unsigned long private,
- struct page *page, int force, enum migrate_mode mode)
+static int unmap_and_move(new_page_t get_new_page, free_page_t put_new_page,
+ unsigned long private, struct page *page, int force,
+ enum migrate_mode mode)
{
int rc = 0;
int *result = NULL;
@@ -986,11 +987,18 @@ out:
page_is_file_cache(page));
putback_lru_page(page);
}
+
/*
- * Move the new page to the LRU. If migration was not successful
- * then this will free the page.
+ * If migration was not successful and there's a freeing callback, use
+ * it. Otherwise, putback_lru_page() will drop the reference grabbed
+ * during isolation.
*/
- putback_lru_page(newpage);
+ if (rc != MIGRATEPAGE_SUCCESS && put_new_page) {
+ ClearPageSwapBacked(newpage);
+ put_new_page(newpage, private);
+ } else
+ putback_lru_page(newpage);
+
if (result) {
if (rc)
*result = rc;
@@ -1019,8 +1027,9 @@ out:
* will wait in the page fault for migration to complete.
*/
static int unmap_and_move_huge_page(new_page_t get_new_page,
- unsigned long private, struct page *hpage,
- int force, enum migrate_mode mode)
+ free_page_t put_new_page, unsigned long private,
+ struct page *hpage, int force,
+ enum migrate_mode mode)
{
int rc = 0;
int *result = NULL;
@@ -1059,20 +1068,30 @@ static int unmap_and_move_huge_page(new_page_t get_new_page,
if (!page_mapped(hpage))
rc = move_to_new_page(new_hpage, hpage, 1, mode);
- if (rc)
+ if (rc != MIGRATEPAGE_SUCCESS)
remove_migration_ptes(hpage, hpage);
if (anon_vma)
put_anon_vma(anon_vma);
- if (!rc)
+ if (rc == MIGRATEPAGE_SUCCESS)
hugetlb_cgroup_migrate(hpage, new_hpage);
unlock_page(hpage);
out:
if (rc != -EAGAIN)
putback_active_hugepage(hpage);
- put_page(new_hpage);
+
+ /*
+ * If migration was not successful and there's a freeing callback, use
+ * it. Otherwise, put_page() will drop the reference grabbed during
+ * isolation.
+ */
+ if (rc != MIGRATEPAGE_SUCCESS && put_new_page)
+ put_new_page(new_hpage, private);
+ else
+ put_page(new_hpage);
+
if (result) {
if (rc)
*result = rc;
@@ -1089,6 +1108,8 @@ out:
* @from: The list of pages to be migrated.
* @get_new_page: The function used to allocate free pages to be used
* as the target of the page migration.
+ * @put_new_page: The function used to free target pages if migration
+ * fails, or NULL if no special handling is necessary.
* @private: Private data to be passed on to get_new_page()
* @mode: The migration mode that specifies the constraints for
* page migration, if any.
@@ -1102,7 +1123,8 @@ out:
* Returns the number of pages that were not migrated, or an error code.
*/
int migrate_pages(struct list_head *from, new_page_t get_new_page,
- unsigned long private, enum migrate_mode mode, int reason)
+ free_page_t put_new_page, unsigned long private,
+ enum migrate_mode mode, int reason)
{
int retry = 1;
int nr_failed = 0;
@@ -1124,10 +1146,11 @@ int migrate_pages(struct list_head *from, new_page_t get_new_page,
if (PageHuge(page))
rc = unmap_and_move_huge_page(get_new_page,
- private, page, pass > 2, mode);
+ put_new_page, private, page,
+ pass > 2, mode);
else
- rc = unmap_and_move(get_new_page, private,
- page, pass > 2, mode);
+ rc = unmap_and_move(get_new_page, put_new_page,
+ private, page, pass > 2, mode);
switch(rc) {
case -ENOMEM:
@@ -1276,7 +1299,7 @@ set_status:
err = 0;
if (!list_empty(&pagelist)) {
- err = migrate_pages(&pagelist, new_page_node,
+ err = migrate_pages(&pagelist, new_page_node, NULL,
(unsigned long)pm, MIGRATE_SYNC, MR_SYSCALL);
if (err)
putback_movable_pages(&pagelist);
@@ -1732,7 +1755,8 @@ int migrate_misplaced_page(struct page *page, struct vm_area_struct *vma,
list_add(&page->lru, &migratepages);
nr_remaining = migrate_pages(&migratepages, alloc_misplaced_dst_page,
- node, MIGRATE_ASYNC, MR_NUMA_MISPLACED);
+ NULL, node, MIGRATE_ASYNC,
+ MR_NUMA_MISPLACED);
if (nr_remaining) {
if (!list_empty(&migratepages)) {
list_del(&page->lru);