On Thu, Jun 30, 2011 at 04:42:31PM +0800, Yongqiang Yang wrote:
> How about:
> next = EXT_MAX_BLOCKS;
> if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block)
> next = ext4_ext_next_leaf_block(inode, path);
> if (next != EXT_MAX_BLOCKS) {
Agreed, that's a better way of doing things. Also, Robin, please
compare and contrast your description with mine. The commit
description shouldn't just be a textual description of the change. It
should give the larger context of the change and why it's important.
- Ted
commit 2a3f7e0e0e55f8817fbe92d111ef2a06e6b8ef18
Author: Robin Dong <sanbai@xxxxxxxxxx>
Date: Mon Jul 11 15:43:38 2011 -0400
ext4: avoid unneeded ext4_ext_next_leaf_block() while inserting extents
Optimize ext4_exT_insert_extent() by avoiding
ext4_ext_next_leaf_block() when the result is not used/needed.
Signed-off-by: Robin Dong <sanbai@xxxxxxxxxx>
Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 9cbdcb2..f1c538e 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -1730,9 +1730,10 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
/* probably next leaf has space for us? */
fex = EXT_LAST_EXTENT(eh);
- next = ext4_ext_next_leaf_block(inode, path);
- if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block)
- && next != EXT_MAX_BLOCKS) {
+ next = EXT_MAX_BLOCKS;
+ if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
+ next = ext4_ext_next_leaf_block(inode, path);
+ if (next != EXT_MAX_BLOCKS) {
ext_debug("next leaf block - %d\n", next);
BUG_ON(npath != NULL);
npath = ext4_ext_find_extent(inode, next, NULL);
--
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