f2fs: adjust showing of extent cache stat

This patch alters to replace total hit stat with rbtree hit stat,
and then adjust showing of extent cache stat:

Hit Count:
L1-1: for largest node hit count;
L1-2: for last cached node hit count;
L2: for extent node hit after lookuping in rbtree.

Hit Ratio:
ratio (hit count / total lookup count)

Inner Struct Count:
tree count, node count.

Before:
Extent Hit Ratio: 0 / 2

Extent Tree Count: 3

Extent Node Count: 2

Patched:
Exten Cacache:
  - Hit Count: L1-1:4871 L1-2:2074 L2:208
  - Hit Ratio: 1% (7153 / 550751)
  - Inner Struct Count: tree: 26560, node: 11824

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

1 files changed, 12 insertions, 6 deletions

diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index 1a1a4c67a9bf..d013d8479753 100644
--- a/fs/f2fs/debug.c
+++ b/fs/f2fs/debug.c
@@ -35,7 +35,8 @@ static void update_general_status(struct f2fs_sb_info *sbi)
         /* validation check of the segment numbers */
         si->hit_largest = atomic_read(&sbi->read_hit_largest);
         si->hit_cached = atomic_read(&sbi->read_hit_cached);
-        si->hit_ext = atomic_read(&sbi->read_hit_ext);
+        si->hit_rbtree = atomic_read(&sbi->read_hit_rbtree);
+        si->hit_total = si->hit_largest + si->hit_cached + si->hit_rbtree;
         si->total_ext = atomic_read(&sbi->total_hit_ext);
         si->ext_tree = sbi->total_ext_tree;
         si->ext_node = atomic_read(&sbi->total_ext_node);
@@ -281,11 +282,16 @@ static int stat_show(struct seq_file *s, void *v)
                                 si->bg_data_blks);
                 seq_printf(s, "  - node blocks : %d (%d)\n", si->node_blks,
                                 si->bg_node_blks);
-                seq_printf(s, "\nExtent Hit Ratio: L1-1:%d L1-2:%d L2:%d / %d\n",
+                seq_puts(s, "\nExtent Cache:\n");
+                seq_printf(s, "  - Hit Count: L1-1:%d L1-2:%d L2:%d\n",
                                 si->hit_largest, si->hit_cached,
-                                si->hit_ext, si->total_ext);
-                seq_printf(s, "\nExtent Tree Count: %d\n", si->ext_tree);
-                seq_printf(s, "\nExtent Node Count: %d\n", si->ext_node);
+                                si->hit_rbtree);
+                seq_printf(s, "  - Hit Ratio: %d%% (%d / %d)\n",
+                                !si->total_ext ? 0 :
+                                (si->hit_total * 100) / si->total_ext,
+                                si->hit_total, si->total_ext);
+                seq_printf(s, "  - Inner Struct Count: tree: %d, node: %d\n",
+                                si->ext_tree, si->ext_node);
                 seq_puts(s, "\nBalancing F2FS Async:\n");
                 seq_printf(s, "  - inmem: %4d, wb: %4d\n",
                            si->inmem_pages, si->wb_pages);
@@ -373,7 +379,7 @@ int f2fs_build_stats(struct f2fs_sb_info *sbi)
         sbi->stat_info = si;
 
         atomic_set(&sbi->total_hit_ext, 0);
-        atomic_set(&sbi->read_hit_ext, 0);
+        atomic_set(&sbi->read_hit_rbtree, 0);
         atomic_set(&sbi->read_hit_largest, 0);
         atomic_set(&sbi->read_hit_cached, 0);