Skip to content

Commit

Permalink
[JFFS2] Optimise jffs2_add_tn_to_list
Browse files Browse the repository at this point in the history 
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>
  • Loading branch information
David Woodhouse authored and Thomas Gleixner committed Jul 6, 2005
1 parent 10c96f2 commit 9dee750
Show file tree
Hide file tree
Showing 3 changed files with 88 additions and 27 deletions.
73 changes: 54 additions & 19 deletions fs/jffs2/nodelist.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@
*
* For licensing information, see the file 'LICENCE' in this directory.
*
* $Id: nodelist.c,v 1.94 2005/04/13 13:22:35 dwmw2 Exp $
* $Id: nodelist.c,v 1.95 2005/07/05 21:03:07 dwmw2 Exp $
*
*/

Expand Down Expand Up @@ -58,27 +58,61 @@ void jffs2_add_fd_to_list(struct jffs2_sb_info *c, struct jffs2_full_dirent *new
/* Put a new tmp_dnode_info into the list, keeping the list in
order of increasing version
*/
static void jffs2_add_tn_to_list(struct jffs2_tmp_dnode_info *tn, struct jffs2_tmp_dnode_info **list)

static void jffs2_add_tn_to_list(struct jffs2_tmp_dnode_info *tn, struct rb_root *list)
{
struct jffs2_tmp_dnode_info **prev = list;

while ((*prev) && (*prev)->version < tn->version) {
prev = &((*prev)->next);
}
tn->next = (*prev);
*prev = tn;
struct rb_node **p = &list->rb_node;
struct rb_node * parent = NULL;
struct jffs2_tmp_dnode_info *this;

while (*p) {
parent = *p;
this = rb_entry(parent, struct jffs2_tmp_dnode_info, rb);

if (tn->version < this->version)
p = &(*p)->rb_left;
else if (tn->version > this->version)
p = &(*p)->rb_right;
else if (tn < this)
p = &(*p)->rb_left;
else
p = &(*p)->rb_right;
}

rb_link_node(&tn->rb, parent, p);
rb_insert_color(&tn->rb, list);
}

static void jffs2_free_tmp_dnode_info_list(struct jffs2_tmp_dnode_info *tn)
static void jffs2_free_tmp_dnode_info_list(struct rb_root *list)
{
struct jffs2_tmp_dnode_info *next;
struct rb_node *this;
struct jffs2_tmp_dnode_info *tn;

this = list->rb_node;

while (tn) {
next = tn;
tn = tn->next;
jffs2_free_full_dnode(next->fn);
jffs2_free_tmp_dnode_info(next);
/* Now at bottom of tree */
while (this) {
if (this->rb_left)
this = this->rb_left;
else if (this->rb_right)
this = this->rb_right;
else {
tn = rb_entry(this, struct jffs2_tmp_dnode_info, rb);
jffs2_free_full_dnode(tn->fn);
jffs2_free_tmp_dnode_info(tn);

this = this->rb_parent;
if (!this)
break;

if (this->rb_left == &tn->rb)
this->rb_left = NULL;
else if (this->rb_right == &tn->rb)
this->rb_right = NULL;
else BUG();
}
}
list->rb_node = NULL;
}

static void jffs2_free_full_dirent_list(struct jffs2_full_dirent *fd)
Expand Down Expand Up @@ -108,12 +142,13 @@ static struct jffs2_raw_node_ref *jffs2_first_valid_node(struct jffs2_raw_node_r
with this ino, returning the former in order of version */

int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
struct jffs2_tmp_dnode_info **tnp, struct jffs2_full_dirent **fdp,
struct rb_root *tnp, struct jffs2_full_dirent **fdp,
uint32_t *highest_version, uint32_t *latest_mctime,
uint32_t *mctime_ver)
{
struct jffs2_raw_node_ref *ref, *valid_ref;
struct jffs2_tmp_dnode_info *tn, *ret_tn = NULL;
struct jffs2_tmp_dnode_info *tn;
struct rb_root ret_tn = RB_ROOT;
struct jffs2_full_dirent *fd, *ret_fd = NULL;
union jffs2_node_union node;
size_t retlen;
Expand Down Expand Up @@ -450,7 +485,7 @@ int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
return 0;

free_out:
jffs2_free_tmp_dnode_info_list(ret_tn);
jffs2_free_tmp_dnode_info_list(&ret_tn);
jffs2_free_full_dirent_list(ret_fd);
return err;
}
Expand Down
6 changes: 3 additions & 3 deletions fs/jffs2/nodelist.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@
*
* For licensing information, see the file 'LICENCE' in this directory.
*
* $Id: nodelist.h,v 1.130 2005/04/09 10:46:59 dedekind Exp $
* $Id: nodelist.h,v 1.131 2005/07/05 21:03:07 dwmw2 Exp $
*
*/

Expand Down Expand Up @@ -161,7 +161,7 @@ struct jffs2_full_dnode
*/
struct jffs2_tmp_dnode_info
{
struct jffs2_tmp_dnode_info *next;
struct rb_node rb;
struct jffs2_full_dnode *fn;
uint32_t version;
};
Expand Down Expand Up @@ -387,7 +387,7 @@ static inline struct jffs2_node_frag *frag_last(struct rb_root *root)
D2(void jffs2_print_frag_list(struct jffs2_inode_info *f));
void jffs2_add_fd_to_list(struct jffs2_sb_info *c, struct jffs2_full_dirent *new, struct jffs2_full_dirent **list);
int jffs2_get_inode_nodes(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
struct jffs2_tmp_dnode_info **tnp, struct jffs2_full_dirent **fdp,
struct rb_root *tnp, struct jffs2_full_dirent **fdp,
uint32_t *highest_version, uint32_t *latest_mctime,
uint32_t *mctime_ver);
void jffs2_set_inocache_state(struct jffs2_sb_info *c, struct jffs2_inode_cache *ic, int state);
Expand Down
36 changes: 31 additions & 5 deletions fs/jffs2/readinode.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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 $
*
*/

Expand Down Expand Up @@ -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;
Expand All @@ -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) {
Expand Down Expand Up @@ -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));
Expand Down

0 comments on commit 9dee750

Please sign in to comment.