f2fs: shrink unreferenced extent_caches first

If an extent_tree entry has a zero reference count, we can drop it from the
cache in higher priority rather than currently referencing entries.

Reviewed-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Jaegeuk Kim 2015-06-29 16:34:39 -07:00
parent bb96a8d51e
commit 7023a1ad17

View File

@ -662,21 +662,54 @@ unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
struct radix_tree_root *root = &sbi->extent_tree_root;
unsigned int found;
unsigned int node_cnt = 0, tree_cnt = 0;
int remained;
if (!test_opt(sbi, EXTENT_CACHE))
return 0;
if (!down_write_trylock(&sbi->extent_tree_lock))
goto out;
/* 1. remove unreferenced extent tree */
while ((found = radix_tree_gang_lookup(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->refcount)) {
write_lock(&et->lock);
node_cnt += __free_extent_tree(sbi, et, true);
write_unlock(&et->lock);
radix_tree_delete(root, et->ino);
kmem_cache_free(extent_tree_slab, et);
sbi->total_ext_tree--;
tree_cnt++;
if (node_cnt + tree_cnt >= nr_shrink)
goto unlock_out;
}
}
}
up_write(&sbi->extent_tree_lock);
/* 2. remove LRU extent entries */
if (!down_write_trylock(&sbi->extent_tree_lock))
goto out;
remained = nr_shrink - (node_cnt + tree_cnt);
spin_lock(&sbi->extent_lock);
list_for_each_entry_safe(en, tmp, &sbi->extent_list, list) {
if (!nr_shrink--)
if (!remained--)
break;
list_del_init(&en->list);
}
spin_unlock(&sbi->extent_lock);
if (!down_write_trylock(&sbi->extent_tree_lock))
goto out;
while ((found = radix_tree_gang_lookup(root,
(void **)treevec, ino, EXT_TREE_VEC_SIZE))) {
unsigned i;
@ -688,14 +721,12 @@ unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
write_lock(&et->lock);
node_cnt += __free_extent_tree(sbi, et, false);
write_unlock(&et->lock);
if (!atomic_read(&et->refcount) && !et->count) {
radix_tree_delete(root, et->ino);
kmem_cache_free(extent_tree_slab, et);
sbi->total_ext_tree--;
tree_cnt++;
}
if (node_cnt + tree_cnt >= nr_shrink)
break;
}
}
unlock_out:
up_write(&sbi->extent_tree_lock);
out:
trace_f2fs_shrink_extent_tree(sbi, node_cnt, tree_cnt);