@@ -1005,56 +1005,17 @@ out:
return rc;
}
-static int __unmap_and_move(struct page *page, struct page *newpage,
- 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,
+ enum migrate_mode mode,
+ enum migrate_reason reason)
{
int rc = -EAGAIN;
int page_was_mapped = 0;
struct anon_vma *anon_vma = NULL;
bool is_lru = !__PageMovable(page);
-
- if (!trylock_page(page)) {
- if (!force || mode == MIGRATE_ASYNC)
- goto out;
-
- /*
- * It's not safe for direct compaction to call lock_page.
- * For example, during page readahead pages are added locked
- * to the LRU. Later, when the IO completes the pages are
- * marked uptodate and unlocked. However, the queueing
- * could be merging multiple pages for one bio (e.g.
- * mpage_readpages). If an allocation happens for the
- * second or third page, the process can end up locking
- * the same page twice and deadlocking. Rather than
- * trying to be clever about what pages can be locked,
- * avoid the use of lock_page for direct compaction
- * altogether.
- */
- if (current->flags & PF_MEMALLOC)
- goto out;
-
- lock_page(page);
- }
-
- if (PageWriteback(page)) {
- /*
- * Only in the case of a full synchronous migration is it
- * necessary to wait for PageWriteback. In the async case,
- * the retry loop is too short and in the sync-light case,
- * the overhead of stalling is too much
- */
- switch (mode) {
- case MIGRATE_SYNC:
- case MIGRATE_SYNC_NO_COPY:
- break;
- default:
- rc = -EBUSY;
- goto out_unlock;
- }
- if (!force)
- goto out_unlock;
- wait_on_page_writeback(page);
- }
+ struct page *newpage;
/*
* By try_to_unmap(), page->mapcount goes down to 0 here. In this case,
@@ -1073,6 +1034,12 @@ static int __unmap_and_move(struct page
if (PageAnon(page) && !PageKsm(page))
anon_vma = page_get_anon_vma(page);
+ newpage = get_new_page(page, private);
+ if (!newpage) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
/*
* Block others from accessing the new page when we get around to
* establishing additional references. We are usually the only one
@@ -1082,11 +1049,11 @@ static int __unmap_and_move(struct page
* This is much like races on refcount of oldpage: just don't BUG().
*/
if (unlikely(!trylock_page(newpage)))
- goto out_unlock;
+ goto out_put;
if (unlikely(!is_lru)) {
rc = move_to_new_page(newpage, page, mode);
- goto out_unlock_both;
+ goto out_unlock;
}
/*
@@ -1105,7 +1072,7 @@ static int __unmap_and_move(struct page
VM_BUG_ON_PAGE(PageAnon(page), page);
if (page_has_private(page)) {
try_to_free_buffers(page);
- goto out_unlock_both;
+ goto out_unlock;
}
} else if (page_mapped(page)) {
/* Establish migration ptes */
@@ -1122,15 +1089,9 @@ static int __unmap_and_move(struct page
if (page_was_mapped)
remove_migration_ptes(page,
rc == MIGRATEPAGE_SUCCESS ? newpage : page, false);
-
-out_unlock_both:
- unlock_page(newpage);
out_unlock:
- /* Drop an anon_vma reference if we took one */
- if (anon_vma)
- put_anon_vma(anon_vma);
- unlock_page(page);
-out:
+ unlock_page(newpage);
+out_put:
/*
* If migration is successful, decrease refcount of the newpage
* which will not free the page because new page owner increased
@@ -1141,12 +1102,20 @@ out:
* state.
*/
if (rc == MIGRATEPAGE_SUCCESS) {
+ set_page_owner_migrate_reason(newpage, reason);
if (unlikely(!is_lru))
put_page(newpage);
else
putback_lru_page(newpage);
+ } else if (put_new_page) {
+ put_new_page(newpage, private);
+ } else {
+ put_page(newpage);
}
-
+out:
+ /* Drop an anon_vma reference if we took one */
+ if (anon_vma)
+ put_anon_vma(anon_vma);
return rc;
}
@@ -1171,16 +1140,11 @@ static ICE_noinline int unmap_and_move(n
int force, enum migrate_mode mode,
enum migrate_reason reason)
{
- int rc = MIGRATEPAGE_SUCCESS;
- struct page *newpage;
+ int rc = -EAGAIN;
if (!thp_migration_supported() && PageTransHuge(page))
return -ENOMEM;
- newpage = get_new_page(page, private);
- if (!newpage)
- return -ENOMEM;
-
if (page_count(page) == 1) {
/* page was freed from under us. So we are done. */
ClearPageActive(page);
@@ -1191,17 +1155,57 @@ static ICE_noinline int unmap_and_move(n
__ClearPageIsolated(page);
unlock_page(page);
}
- if (put_new_page)
- put_new_page(newpage, private);
- else
- put_page(newpage);
+ rc = MIGRATEPAGE_SUCCESS;
goto out;
}
- rc = __unmap_and_move(page, newpage, force, mode);
- if (rc == MIGRATEPAGE_SUCCESS)
- set_page_owner_migrate_reason(newpage, reason);
+ if (!trylock_page(page)) {
+ if (!force || mode == MIGRATE_ASYNC)
+ return rc;
+
+ /*
+ * It's not safe for direct compaction to call lock_page.
+ * For example, during page readahead pages are added locked
+ * to the LRU. Later, when the IO completes the pages are
+ * marked uptodate and unlocked. However, the queueing
+ * could be merging multiple pages for one bio (e.g.
+ * mpage_readpages). If an allocation happens for the
+ * second or third page, the process can end up locking
+ * the same page twice and deadlocking. Rather than
+ * trying to be clever about what pages can be locked,
+ * avoid the use of lock_page for direct compaction
+ * altogether.
+ */
+ if (current->flags & PF_MEMALLOC)
+ return rc;
+ lock_page(page);
+ }
+
+ if (PageWriteback(page)) {
+ /*
+ * Only in the case of a full synchronous migration is it
+ * necessary to wait for PageWriteback. In the async case,
+ * the retry loop is too short and in the sync-light case,
+ * the overhead of stalling is too much
+ */
+ switch (mode) {
+ case MIGRATE_SYNC:
+ case MIGRATE_SYNC_NO_COPY:
+ break;
+ default:
+ rc = -EBUSY;
+ goto out_unlock;
+ }
+ if (!force)
+ goto out_unlock;
+ wait_on_page_writeback(page);
+ }
+ rc = __unmap_and_move(get_new_page, put_new_page, private,
+ page, mode, reason);
+
+out_unlock:
+ unlock_page(page);
out:
if (rc != -EAGAIN) {
/*
@@ -1242,9 +1246,8 @@ out:
if (rc != -EAGAIN) {
if (likely(!__PageMovable(page))) {
putback_lru_page(page);
- goto put_new;
+ goto done;
}
-
lock_page(page);
if (PageMovable(page))
putback_movable_page(page);
@@ -1253,13 +1256,8 @@ out:
unlock_page(page);
put_page(page);
}
-put_new:
- if (put_new_page)
- put_new_page(newpage, private);
- else
- put_page(newpage);
}
-
+done:
return rc;
}