From ea64ab87cdba9e1172392d247e6526359e301f12 Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Tue, 13 Jul 2010 23:33:52 +0900 Subject: [PATCH] nilfs2: optimize calculation of min/max number of btree node children nilfs_btree_node_nchildren_max() and nilfs_btree_node_nchildren_min() functions switch return value depending on whether target node is the root or a node block. In most uses of these functions, however, the node type is fixed, and moreover the same calculation is repeatedly performed in loop. This unfold these functions depending on context and move them outside loops wherever possible. Signed-off-by: Ryusuke Konishi --- fs/nilfs2/btree.c | 36 ++++++++++++++++++------------------ 1 file changed, 18 insertions(+), 18 deletions(-) diff --git a/fs/nilfs2/btree.c b/fs/nilfs2/btree.c index 18bb965c66b5..c0266f7f0b26 100644 --- a/fs/nilfs2/btree.c +++ b/fs/nilfs2/btree.c @@ -473,7 +473,7 @@ static int nilfs_btree_do_lookup(const struct nilfs_bmap *btree, { struct nilfs_btree_node *node; __u64 ptr; - int level, index, found, ret; + int level, index, found, ncmax, ret; node = nilfs_btree_get_root(btree); level = nilfs_btree_node_get_level(node); @@ -485,6 +485,8 @@ static int nilfs_btree_do_lookup(const struct nilfs_bmap *btree, path[level].bp_bh = NULL; path[level].bp_index = index; + ncmax = NILFS_BTREE_NODE_NCHILDREN_MAX(nilfs_btree_node_size(btree)); + for (level--; level >= minlevel; level--) { ret = nilfs_btree_get_block(btree, ptr, &path[level].bp_bh); if (ret < 0) @@ -496,9 +498,9 @@ static int nilfs_btree_do_lookup(const struct nilfs_bmap *btree, found = nilfs_btree_node_lookup(node, key, &index); else index = 0; - if (index < nilfs_btree_node_nchildren_max(node, btree)) + if (index < ncmax) { ptr = nilfs_btree_node_get_ptr(btree, node, index); - else { + } else { WARN_ON(found || level != NILFS_BTREE_LEVEL_NODE_MIN); /* insert */ ptr = NILFS_BMAP_INVALID_PTR; @@ -921,7 +923,7 @@ static int nilfs_btree_prepare_insert(struct nilfs_bmap *btree, struct buffer_head *bh; struct nilfs_btree_node *node, *parent, *sib; __u64 sibptr; - int pindex, level, ret; + int pindex, level, ncmax, ret; struct inode *dat = NULL; stats->bs_nblocks = 0; @@ -938,12 +940,13 @@ static int nilfs_btree_prepare_insert(struct nilfs_bmap *btree, if (ret < 0) goto err_out_data; + ncmax = NILFS_BTREE_NODE_NCHILDREN_MAX(nilfs_btree_node_size(btree)); + for (level = NILFS_BTREE_LEVEL_NODE_MIN; level < nilfs_btree_height(btree) - 1; level++) { node = nilfs_btree_get_nonroot_node(path, level); - if (nilfs_btree_node_get_nchildren(node) < - nilfs_btree_node_nchildren_max(node, btree)) { + if (nilfs_btree_node_get_nchildren(node) < ncmax) { path[level].bp_op = nilfs_btree_do_insert; stats->bs_nblocks++; goto out; @@ -960,8 +963,7 @@ static int nilfs_btree_prepare_insert(struct nilfs_bmap *btree, if (ret < 0) goto err_out_child_node; sib = (struct nilfs_btree_node *)bh->b_data; - if (nilfs_btree_node_get_nchildren(sib) < - nilfs_btree_node_nchildren_max(sib, btree)) { + if (nilfs_btree_node_get_nchildren(sib) < ncmax) { path[level].bp_sib_bh = bh; path[level].bp_op = nilfs_btree_carry_left; stats->bs_nblocks++; @@ -979,8 +981,7 @@ static int nilfs_btree_prepare_insert(struct nilfs_bmap *btree, if (ret < 0) goto err_out_child_node; sib = (struct nilfs_btree_node *)bh->b_data; - if (nilfs_btree_node_get_nchildren(sib) < - nilfs_btree_node_nchildren_max(sib, btree)) { + if (nilfs_btree_node_get_nchildren(sib) < ncmax) { path[level].bp_sib_bh = bh; path[level].bp_op = nilfs_btree_carry_right; stats->bs_nblocks++; @@ -1014,7 +1015,7 @@ static int nilfs_btree_prepare_insert(struct nilfs_bmap *btree, /* root */ node = nilfs_btree_get_root(btree); if (nilfs_btree_node_get_nchildren(node) < - nilfs_btree_node_nchildren_max(node, btree)) { + NILFS_BTREE_ROOT_NCHILDREN_MAX) { path[level].bp_op = nilfs_btree_do_insert; stats->bs_nblocks++; goto out; @@ -1281,10 +1282,12 @@ static int nilfs_btree_prepare_delete(struct nilfs_bmap *btree, struct buffer_head *bh; struct nilfs_btree_node *node, *parent, *sib; __u64 sibptr; - int pindex, level, ret; + int pindex, level, ncmin, ret; ret = 0; stats->bs_nblocks = 0; + ncmin = NILFS_BTREE_NODE_NCHILDREN_MIN(nilfs_btree_node_size(btree)); + for (level = NILFS_BTREE_LEVEL_NODE_MIN; level < nilfs_btree_height(btree) - 1; level++) { @@ -1297,8 +1300,7 @@ static int nilfs_btree_prepare_delete(struct nilfs_bmap *btree, if (ret < 0) goto err_out_child_node; - if (nilfs_btree_node_get_nchildren(node) > - nilfs_btree_node_nchildren_min(node, btree)) { + if (nilfs_btree_node_get_nchildren(node) > ncmin) { path[level].bp_op = nilfs_btree_do_delete; stats->bs_nblocks++; goto out; @@ -1315,8 +1317,7 @@ static int nilfs_btree_prepare_delete(struct nilfs_bmap *btree, if (ret < 0) goto err_out_curr_node; sib = (struct nilfs_btree_node *)bh->b_data; - if (nilfs_btree_node_get_nchildren(sib) > - nilfs_btree_node_nchildren_min(sib, btree)) { + if (nilfs_btree_node_get_nchildren(sib) > ncmin) { path[level].bp_sib_bh = bh; path[level].bp_op = nilfs_btree_borrow_left; stats->bs_nblocks++; @@ -1336,8 +1337,7 @@ static int nilfs_btree_prepare_delete(struct nilfs_bmap *btree, if (ret < 0) goto err_out_curr_node; sib = (struct nilfs_btree_node *)bh->b_data; - if (nilfs_btree_node_get_nchildren(sib) > - nilfs_btree_node_nchildren_min(sib, btree)) { + if (nilfs_btree_node_get_nchildren(sib) > ncmin) { path[level].bp_sib_bh = bh; path[level].bp_op = nilfs_btree_borrow_right; stats->bs_nblocks++; -- 2.20.1