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authorFrans van de Wiel <fvdw@fvdw.eu>2010-03-15 19:29:34 +0100
committerJan Kara <jack@suse.cz>2010-05-21 19:30:36 +0200
commit8cef107a1d890ff76c85d665083ff3562be01d32 (patch)
treed8cb4a9acc01d110efeb43e2e9591f43596d5a16
parent70ca0a42fe1702ac0784386c44b05d18ee5f1f9e (diff)
downloadop-kernel-dev-8cef107a1d890ff76c85d665083ff3562be01d32.zip
op-kernel-dev-8cef107a1d890ff76c85d665083ff3562be01d32.tar.gz
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" <fvdw@fvdw.eu> Signed-off-by: Jan Kara <jack@suse.cz>
-rw-r--r--fs/ext3/balloc.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/fs/ext3/balloc.c b/fs/ext3/balloc.c
index a177122..4a32511 100644
--- a/fs/ext3/balloc.c
+++ b/fs/ext3/balloc.c
@@ -1584,6 +1584,12 @@ retry_alloc:
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
* window size.
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