leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

f2fs: improve shrink performance of extent nodes

Browse Source 
On the worst case, we need to scan the whole radix tree and every rb-tree to
free the victimed extent_nodes when shrinking.

Pengyang initially introduced a victim_list to record the victimed extent_nodes,
and free these extent_nodes by just scanning a list.

Later, Chao Yu enhances the original patch to improve memory footprint by
removing victim list.

The policy of lru list shrinking becomes:
1) lock lru list's lock
2) trylock extent tree's lock
3) remove extent node from lru list
4) unlock lru list's lock
5) do shrink
6) repeat 1) to 5)

Signed-off-by: Hou Pengyang <houpengyang@huawei.com>
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Hou Pengyang 2016-01-26 12:56:26 +00:00 committed by Jaegeuk Kim
parent 429267442a
commit 201ef5e080
2 changed files with 29 additions and 48 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

76
fs/f2fs/extent_cache.c
View File

@ -33,6 +33,7 @@ static struct extent_node *__attach_extent_node(struct f2fs_sb_info *sbi,
en->ei = *ei;
INIT_LIST_HEAD(&en->list);
en->et = et;
rb_link_node(&en->rb_node, parent, p);
rb_insert_color(&en->rb_node, &et->root);
@ -63,8 +64,8 @@ static void __release_extent_node(struct f2fs_sb_info *sbi,
struct extent_tree *et, struct extent_node *en)
{
spin_lock(&sbi->extent_lock);
if (!list_empty(&en->list))
list_del_init(&en->list);
f2fs_bug_on(sbi, list_empty(&en->list));
list_del_init(&en->list);
spin_unlock(&sbi->extent_lock);
__detach_extent_node(sbi, et, en);
@ -147,7 +148,7 @@ static struct extent_node *__init_extent_tree(struct f2fs_sb_info *sbi,
}
static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi,
struct extent_tree *et, bool free_all)
struct extent_tree *et)
{
struct rb_node *node, *next;
struct extent_node *en;
@ -157,11 +158,7 @@ static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi,
while (node) {
next = rb_next(node);
en = rb_entry(node, struct extent_node, rb_node);
if (free_all)
__release_extent_node(sbi, et, en);
else if (list_empty(&en->list))
__detach_extent_node(sbi, et, en);
__release_extent_node(sbi, et, en);
node = next;
}
@ -532,7 +529,7 @@ static unsigned int f2fs_update_extent_tree_range(struct inode *inode,
}
if (is_inode_flag_set(F2FS_I(inode), FI_NO_EXTENT))
__free_extent_tree(sbi, et, true);
__free_extent_tree(sbi, et);
write_unlock(&et->lock);
@ -541,14 +538,10 @@ static unsigned int f2fs_update_extent_tree_range(struct inode *inode,
unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
{
struct extent_tree *treevec[EXT_TREE_VEC_SIZE];
struct extent_tree *et, *next;
struct extent_node *en, *tmp;
unsigned long ino = F2FS_ROOT_INO(sbi);
unsigned int found;
struct extent_node *en;
unsigned int node_cnt = 0, tree_cnt = 0;
int remained;
bool do_free = false;
if (!test_opt(sbi, EXTENT_CACHE))
return 0;
@ -563,10 +556,10 @@ unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
list_for_each_entry_safe(et, next, &sbi->zombie_list, list) {
if (atomic_read(&et->node_cnt)) {
write_lock(&et->lock);
node_cnt += __free_extent_tree(sbi, et, true);
node_cnt += __free_extent_tree(sbi, et);
write_unlock(&et->lock);
}
f2fs_bug_on(sbi, atomic_read(&et->node_cnt));
list_del_init(&et->list);
radix_tree_delete(&sbi->extent_tree_root, et->ino);
kmem_cache_free(extent_tree_slab, et);
@ -587,42 +580,29 @@ free_node:
remained = nr_shrink - (node_cnt + tree_cnt);
spin_lock(&sbi->extent_lock);
list_for_each_entry_safe(en, tmp, &sbi->extent_list, list) {
if (!remained--)
for (; remained > 0; remained--) {
if (list_empty(&sbi->extent_list))
break;
en = list_first_entry(&sbi->extent_list,
struct extent_node, list);
et = en->et;
if (!write_trylock(&et->lock)) {
/* refresh this extent node's position in extent list */
list_move_tail(&en->list, &sbi->extent_list);
continue;
}
list_del_init(&en->list);
do_free = true;
spin_unlock(&sbi->extent_lock);
__detach_extent_node(sbi, et, en);
write_unlock(&et->lock);
node_cnt++;
spin_lock(&sbi->extent_lock);
}
spin_unlock(&sbi->extent_lock);
if (do_free == false)
goto unlock_out;
/*
* reset ino for searching victims from beginning of global extent tree.
*/
ino = F2FS_ROOT_INO(sbi);
while ((found = radix_tree_gang_lookup(&sbi->extent_tree_root,
(void **)treevec, ino, EXT_TREE_VEC_SIZE))) {
unsigned i;
ino = treevec[found - 1]->ino + 1;
for (i = 0; i < found; i++) {
struct extent_tree *et = treevec[i];
if (!atomic_read(&et->node_cnt))
continue;
if (write_trylock(&et->lock)) {
node_cnt += __free_extent_tree(sbi, et, false);
write_unlock(&et->lock);
}
if (node_cnt + tree_cnt >= nr_shrink)
goto unlock_out;
}
}
unlock_out:
up_write(&sbi->extent_tree_lock);
out:
@ -641,7 +621,7 @@ unsigned int f2fs_destroy_extent_node(struct inode *inode)
return 0;
write_lock(&et->lock);
node_cnt = __free_extent_tree(sbi, et, true);
node_cnt = __free_extent_tree(sbi, et);
write_unlock(&et->lock);
return node_cnt;

1
fs/f2fs/f2fs.h
View File

@ -354,6 +354,7 @@ struct extent_node {
struct rb_node rb_node; /* rb node located in rb-tree */
struct list_head list; /* node in global extent list of sbi */
struct extent_info ei; /* extent info */
struct extent_tree *et; /* extent tree pointer */
};
struct extent_tree {