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| author | David Woodhouse <dwmw2@infradead.org> | 2005-07-05 22:03:10 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@mtd.linutronix.de> | 2005-07-06 14:07:54 +0200 |
| commit | 9dee7503ce3fc38911b9873216619190cf688128 (patch) | |
| tree | 4a980e7afd14722a81472600ed13e147ff69f923 /fs/jffs2/readinode.c | |
| parent | 10c96f2ec37f5369a785cf8c5a065a15e323c743 (diff) | |
| download | linux-3.10-9dee7503ce3fc38911b9873216619190cf688128.tar.gz linux-3.10-9dee7503ce3fc38911b9873216619190cf688128.tar.bz2 linux-3.10-9dee7503ce3fc38911b9873216619190cf688128.zip | |
[JFFS2] Optimise jffs2_add_tn_to_list
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>
Diffstat (limited to 'fs/jffs2/readinode.c')
| -rw-r--r-- | fs/jffs2/readinode.c | 36 |
1 files changed, 31 insertions, 5 deletions
diff --git a/fs/jffs2/readinode.c b/fs/jffs2/readinode.c index ef552477c81..081656c1d49 100644 --- a/fs/jffs2/readinode.c +++ b/fs/jffs2/readinode.c @@ -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)); |