From 46891532370e862d6bddedef9e6ca22a59a51fa4 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Mon, 29 Mar 2010 13:55:39 +0200 Subject: [PATCH] ext2: Avoid loading bitmaps for full groups during block allocation There is no point in loading bitmap for groups which are completely full. This causes noticeable performance problems (and memory pressure) on small systems with large full filesystem (http://marc.info/?l=linux-ext4&m=126843108314310&w=2). Port of the same ext3 patch. Signed-off-by: Jan Kara --- fs/ext2/balloc.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c index 3cf038c0..e8766a3 100644 --- a/fs/ext2/balloc.c +++ b/fs/ext2/balloc.c @@ -1332,6 +1332,12 @@ retry_alloc: free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); /* + * skip this group (and avoid loading bitmap) if there + * are no free blocks + */ + if (!free_blocks) + continue; + /* * skip this group if the number of * free blocks is less than half of the reservation * window size. -- 2.7.4