renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-11-19 08:05:27 +08:00
Code

UBIFS: improve garbage collection

Browse Source 
Make garbage collection try to keep data nodes from the same
inode together and in ascending order.  This improves
performance when reading those nodes especially when bulk-read
is used.

Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
This commit is contained in:
Adrian Hunter 2008-09-11 12:57:49 +03:00 committed by Artem Bityutskiy
parent bed79935de
commit 46773be497
1 changed files with 72 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

82
fs/ubifs/gc.c
View File

@ -95,6 +95,48 @@ static int switch_gc_head(struct ubifs_info *c)
return err;
}
/**
* joinup - bring data nodes for an inode together.
* @c: UBIFS file-system description object
* @sleb: describes scanned LEB
* @inum: inode number
* @blk: block number
* @data: list to which to add data nodes
*
* This function looks at the first few nodes in the scanned LEB @sleb and adds
* them to @data if they are data nodes from @inum and have a larger block
* number than @blk. This function returns %0 on success and a negative error
* code on failure.
*/
static int joinup(struct ubifs_info *c, struct ubifs_scan_leb *sleb, ino_t inum,
unsigned int blk, struct list_head *data)
{
int err, cnt = 6, lnum = sleb->lnum, offs;
struct ubifs_scan_node *snod, *tmp;
union ubifs_key *key;
list_for_each_entry_safe(snod, tmp, &sleb->nodes, list) {
key = &snod->key;
if (key_inum(c, key) == inum &&
key_type(c, key) == UBIFS_DATA_KEY &&
key_block(c, key) > blk) {
offs = snod->offs;
err = ubifs_tnc_has_node(c, key, 0, lnum, offs, 0);
if (err < 0)
return err;
list_del(&snod->list);
if (err) {
list_add_tail(&snod->list, data);
blk = key_block(c, key);
} else
kfree(snod);
cnt = 6;
} else if (--cnt == 0)
break;
}
return 0;
}
/**
* move_nodes - move nodes.
* @c: UBIFS file-system description object
@ -116,16 +158,21 @@ static int switch_gc_head(struct ubifs_info *c)
static int move_nodes(struct ubifs_info *c, struct ubifs_scan_leb *sleb)
{
struct ubifs_scan_node *snod, *tmp;
struct list_head large, medium, small;
struct list_head data, large, medium, small;
struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf;
int avail, err, min = INT_MAX;
unsigned int blk = 0;
ino_t inum = 0;
INIT_LIST_HEAD(&data);
INIT_LIST_HEAD(&large);
INIT_LIST_HEAD(&medium);
INIT_LIST_HEAD(&small);
list_for_each_entry_safe(snod, tmp, &sleb->nodes, list) {
struct list_head *lst;
while (!list_empty(&sleb->nodes)) {
struct list_head *lst = sleb->nodes.next;
snod = list_entry(lst, struct ubifs_scan_node, list);
ubifs_assert(snod->type != UBIFS_IDX_NODE);
ubifs_assert(snod->type != UBIFS_REF_NODE);
@ -136,7 +183,6 @@ static int move_nodes(struct ubifs_info *c, struct ubifs_scan_leb *sleb)
if (err < 0)
goto out;
lst = &snod->list;
list_del(lst);
if (!err) {
/* The node is obsolete, remove it from the list */
@ -145,15 +191,30 @@ static int move_nodes(struct ubifs_info *c, struct ubifs_scan_leb *sleb)
}
/*
* Sort the list of nodes so that large nodes go first, and
* small nodes go last.
* Sort the list of nodes so that data nodes go first, large
* nodes go second, and small nodes go last.
*/
if (snod->len > MEDIUM_NODE_WM)
list_add(lst, &large);
if (key_type(c, &snod->key) == UBIFS_DATA_KEY) {
if (inum != key_inum(c, &snod->key)) {
if (inum) {
/*
* Try to move data nodes from the same
* inode together.
*/
err = joinup(c, sleb, inum, blk, &data);
if (err)
goto out;
}
inum = key_inum(c, &snod->key);
blk = key_block(c, &snod->key);
}
list_add_tail(lst, &data);
} else if (snod->len > MEDIUM_NODE_WM)
list_add_tail(lst, &large);
else if (snod->len > SMALL_NODE_WM)
list_add(lst, &medium);
list_add_tail(lst, &medium);
else
list_add(lst, &small);
list_add_tail(lst, &small);
/* And find the smallest node */
if (snod->len < min)
@ -164,6 +225,7 @@ static int move_nodes(struct ubifs_info *c, struct ubifs_scan_leb *sleb)
* Join the tree lists so that we'd have one roughly sorted list
* ('large' will be the head of the joined list).
*/
list_splice(&data, &large);
list_splice(&medium, large.prev);
list_splice(&small, large.prev);