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authorJan Kara <jack@suse.cz>2010-03-29 13:55:39 +0200
committerJan Kara <jack@suse.cz>2010-05-21 19:30:37 +0200
commit46891532370e862d6bddedef9e6ca22a59a51fa4 (patch)
tree0e4d6128f7f4a1f67d6c3ede3504100ec5d5ee7a
parent8cef107a1d890ff76c85d665083ff3562be01d32 (diff)
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 <jack@suse.cz>
-rw-r--r--fs/ext2/balloc.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
index 3cf038c055d..e8766a39677 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.