[PATCH 5/9] f2fs: adjust showing of extent cache stat

From: Chao Yu
Date: Wed Aug 19 2015 - 07:14:13 EST

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@xxxxxxxxxxx>
---
fs/f2fs/debug.c | 18 ++++++++++++------
fs/f2fs/extent_cache.c | 10 +++++-----
fs/f2fs/f2fs.h | 9 +++++----
3 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index 1a1a4c6..d013d84 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);

diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
index 5cf217f..d11735a 100644
--- a/fs/f2fs/extent_cache.c
+++ b/fs/f2fs/extent_cache.c
@@ -99,12 +99,14 @@ static struct extent_node *__lookup_extent_tree(struct f2fs_sb_info *sbi,
while (node) {
en = rb_entry(node, struct extent_node, rb_node);

- if (fofs < en->ei.fofs)
+ if (fofs < en->ei.fofs) {
node = node->rb_left;
- else if (fofs >= en->ei.fofs + en->ei.len)
+ } else if (fofs >= en->ei.fofs + en->ei.len) {
node = node->rb_right;
- else
+ } else {
+ stat_inc_rbtree_node_hit(sbi);
return en;
+ }
}
return NULL;
}
@@ -281,7 +283,6 @@ static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
et->largest.fofs + et->largest.len > pgofs) {
*ei = et->largest;
ret = true;
- stat_inc_read_hit(sbi);
stat_inc_largest_node_hit(sbi);
goto out;
}
@@ -295,7 +296,6 @@ static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
et->cached_en = en;
spin_unlock(&sbi->extent_lock);
ret = true;
- stat_inc_read_hit(sbi);
}
out:
stat_inc_total_hit(sbi);
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 632cc37..68c5acd 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -793,7 +793,7 @@ struct f2fs_sb_info {
unsigned int block_count[2]; /* # of allocated blocks */
atomic_t inplace_count; /* # of inplace update */
atomic_t total_hit_ext; /* # of lookup extent cache */
- atomic_t read_hit_ext; /* # of hit extent cache */
+ atomic_t read_hit_rbtree; /* # of hit rbtree extent node */
atomic_t read_hit_largest; /* # of hit largest extent node */
atomic_t read_hit_cached; /* # of hit cached extent node */
atomic_t inline_xattr; /* # of inline_xattr inodes */
@@ -1841,7 +1841,8 @@ struct f2fs_stat_info {
struct f2fs_sb_info *sbi;
int all_area_segs, sit_area_segs, nat_area_segs, ssa_area_segs;
int main_area_segs, main_area_sections, main_area_zones;
- int hit_largest, hit_cached, hit_ext, total_ext, ext_tree, ext_node;
+ int hit_largest, hit_cached, hit_rbtree, hit_total, total_ext;
+ int ext_tree, ext_node;
int ndirty_node, ndirty_dent, ndirty_dirs, ndirty_meta;
int nats, dirty_nats, sits, dirty_sits, fnids;
int total_count, utilization;
@@ -1878,7 +1879,7 @@ static inline struct f2fs_stat_info *F2FS_STAT(struct f2fs_sb_info *sbi)
#define stat_inc_dirty_dir(sbi) ((sbi)->n_dirty_dirs++)
#define stat_dec_dirty_dir(sbi) ((sbi)->n_dirty_dirs--)
#define stat_inc_total_hit(sbi) (atomic_inc(&(sbi)->total_hit_ext))
-#define stat_inc_read_hit(sbi) (atomic_inc(&(sbi)->read_hit_ext))
+#define stat_inc_rbtree_node_hit(sbi) (atomic_inc(&(sbi)->read_hit_rbtree))
#define stat_inc_largest_node_hit(sbi) (atomic_inc(&(sbi)->read_hit_largest))
#define stat_inc_cached_node_hit(sbi) (atomic_inc(&(sbi)->read_hit_cached))
#define stat_inc_inline_xattr(inode) \
@@ -1960,7 +1961,7 @@ void f2fs_destroy_root_stats(void);
#define stat_inc_dirty_dir(sbi)
#define stat_dec_dirty_dir(sbi)
#define stat_inc_total_hit(sb)
-#define stat_inc_read_hit(sb)
+#define stat_inc_rbtree_node_hit(sb)
#define stat_inc_largest_node_hit(sbi)
#define stat_inc_cached_node_hit(sbi)
#define stat_inc_inline_xattr(inode)
--
2.4.2


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