writeback: don't resort for a single super_block in move_expired_inodes()

If we only moved inodes from a single super_block to the temporary list, there's no point in doing a resort for multiple super_blocks. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

writeback: don't resort for a single super_block in move_expired_inodes()
If we only moved inodes from a single super_block to the temporary list, there's no point in doing a resort for multiple super_blocks. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Jens Axboe
1 parent 5c03449d34
Showing 1 changed file with 11 additions and 1 deletions Side-by-side Diff
fs/fs-writeback.c
@@ -336,15 +336,25 @@
 {
 	LIST_HEAD(tmp);
 	struct list_head *pos, *node;
-	struct super_block *sb;
+	struct super_block *sb = NULL;
 	struct inode *inode;
+	int do_sb_sort = 0;
  
 	while (!list_empty(delaying_queue)) {
 		inode = list_entry(delaying_queue->prev, struct inode, i_list);
 		if (older_than_this &&
 		    inode_dirtied_after(inode, *older_than_this))
 			break;
+		if (sb && sb != inode->i_sb)
+			do_sb_sort = 1;
+		sb = inode->i_sb;
 		list_move(&inode->i_list, &tmp);
+	}
+
+	/* just one sb in list, splice to dispatch_queue and we're done */
+	if (!do_sb_sort) {
+		list_splice(&tmp, dispatch_queue);
+		return;
 	}
  
 	/* Move inodes from one superblock together */
...	...	@@ -336,15 +336,25 @@
336	336	{
337	337	LIST_HEAD(tmp);
338	338	struct list_head pos, node;
339		- struct super_block *sb;
	339	+ struct super_block *sb = NULL;
340	340	struct inode *inode;
	341	+ int do_sb_sort = 0;
341	342
342	343	while (!list_empty(delaying_queue)) {
343	344	inode = list_entry(delaying_queue->prev, struct inode, i_list);
344	345	if (older_than_this &&
345	346	inode_dirtied_after(inode, *older_than_this))
346	347	break;
	348	+ if (sb && sb != inode->i_sb)
	349	+ do_sb_sort = 1;
	350	+ sb = inode->i_sb;
347	351	list_move(&inode->i_list, &tmp);
	352	+ }
	353	+
	354	+ /* just one sb in list, splice to dispatch_queue and we're done */
	355	+ if (!do_sb_sort) {
	356	+ list_splice(&tmp, dispatch_queue);
	357	+ return;
348	358	}
349	359
350	360	/* Move inodes from one superblock together */