From: Frans van de Wiel Date: Mon, 15 Mar 2010 18:29:34 +0000 (+0100) Subject: ext3: Avoid loading bitmaps for full groups during block allocation X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=8cef107a1d890ff76c85d665083ff3562be01d32;p=mv-sheeva.git ext3: 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). Jan Kara: Added a comment and changed check to use cpu-endian value. Signed-off-by: "Frans van de Wiel" Signed-off-by: Jan Kara --- diff --git a/fs/ext3/balloc.c b/fs/ext3/balloc.c index a177122a1b2..4a32511f4de 100644 --- a/fs/ext3/balloc.c +++ b/fs/ext3/balloc.c @@ -1583,6 +1583,12 @@ retry_alloc: if (!gdp) goto io_error; 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