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[JFFS2] Optimise jffs2_add_tn_to_list

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Use an rbtree instead of a simple linked list. We were wasting 
an amazing amount of time in jffs2_add_tn_to_list(). 
Thanks to Artem Bityuckiy and Jarkko Jlavinen  for noticing.

Signed-off-by: David Woodhouse <dwmw2@infradead.org> 
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
David Woodhouse
2005-07-05 22:03:10 +01:00
committed by Thomas Gleixner
parent 10c96f2ec3
commit 9dee7503ce
3 changed files with 88 additions and 27 deletions
Download Patch File Download Diff File Expand all files Collapse all files
fs/jffs2/readinode.c
+31 -5
View File
@@ -7,7 +7,7 @@
*
* For licensing information, see the file 'LICENCE' in this directory.
*
* $Id: readinode.c,v 1.119 2005/03/01 10:34:03 dedekind Exp $
* $Id: readinode.c,v 1.120 2005/07/05 21:03:07 dwmw2 Exp $
*
*/
@@ -500,7 +500,9 @@ static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c,
struct jffs2_inode_info *f,
struct jffs2_raw_inode *latest_node)
{
struct jffs2_tmp_dnode_info *tn_list, *tn;
struct jffs2_tmp_dnode_info *tn = NULL;
struct rb_root tn_list;
struct rb_node *rb, *repl_rb;
struct jffs2_full_dirent *fd_list;
struct jffs2_full_dnode *fn = NULL;
uint32_t crc;
@@ -522,9 +524,10 @@ static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c,
}
f->dents = fd_list;
while (tn_list) {
tn = tn_list;
rb = rb_first(&tn_list);
while (rb) {
tn = rb_entry(rb, struct jffs2_tmp_dnode_info, rb);
fn = tn->fn;
if (f->metadata) {
@@ -556,7 +559,30 @@ static int jffs2_do_read_inode_internal(struct jffs2_sb_info *c,
mdata_ver = tn->version;
}
next_tn:
tn_list = tn->next;
BUG_ON(rb->rb_left);
repl_rb = NULL;
if (rb->rb_parent && rb->rb_parent->rb_left == rb) {
/* We were then left-hand child of our parent. We need
to move our own right-hand child into our place. */
repl_rb = rb->rb_right;
if (repl_rb)
repl_rb->rb_parent = rb->rb_parent;
} else
repl_rb = NULL;
rb = rb_next(rb);
/* Remove the spent tn from the tree; don't bother rebalancing
but put our right-hand child in our own place. */
if (tn->rb.rb_parent) {
if (tn->rb.rb_parent->rb_left == &tn->rb)
tn->rb.rb_parent->rb_left = repl_rb;
else if (tn->rb.rb_parent->rb_right == &tn->rb)
tn->rb.rb_parent->rb_right = repl_rb;
else BUG();
} else if (tn->rb.rb_right)
tn->rb.rb_right->rb_parent = NULL;
jffs2_free_tmp_dnode_info(tn);
}
D1(jffs2_sanitycheck_fragtree(f));