bcachefs: Rename lock_held_stats -> btree_transaction_stats

Going to be adding more things to this in the next patch.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/bcachefs.h

@@ -319,8 +319,6 @@ BCH_DEBUG_PARAMS_DEBUG()
 #undef BCH_DEBUG_PARAM
 #endif
 
-#define BCH_LOCK_TIME_NR 128
-
 #define BCH_TIME_STATS()			\
 	x(btree_node_mem_alloc)			\
 	x(btree_node_split)			\
@@ -529,9 +527,10 @@ struct btree_debug {
 	unsigned		id;
 };
 
-struct lock_held_stats {
-	struct bch2_time_stats	times[BCH_LOCK_TIME_NR];
-	const char		*names[BCH_LOCK_TIME_NR];
+#define BCH_TRANSACTIONS_NR 128
+
+struct btree_transaction_stats {
+	struct bch2_time_stats	lock_hold_times;
 };
 
 struct bch_fs_pcpu {
@@ -928,7 +927,8 @@ mempool_t		bio_bounce_pages;
 
 	struct bch2_time_stats	times[BCH_TIME_STAT_NR];
 
-	struct lock_held_stats	lock_held_stats;
+	const char              *btree_transaction_fns[BCH_TRANSACTIONS_NR];
+	struct btree_transaction_stats btree_transaction_stats[BCH_TRANSACTIONS_NR];
 };
 
 static inline void bch2_set_ra_pages(struct bch_fs *c, unsigned ra_pages)

fs/bcachefs/btree_iter.c

@@ -3252,6 +3252,22 @@ static void bch2_trans_alloc_paths(struct btree_trans *trans, struct bch_fs *c)
 	trans->updates		= p; p += updates_bytes;
 }
 
+static inline unsigned bch2_trans_get_fn_idx(struct btree_trans *trans, struct bch_fs *c,
+					const char *fn)
+{
+	unsigned i;
+
+	for (i = 0; i < ARRAY_SIZE(c->btree_transaction_fns); i++)
+		if (!c->btree_transaction_fns[i] ||
+		    c->btree_transaction_fns[i] == fn) {
+			c->btree_transaction_fns[i] = fn;
+			return i;
+		}
+
+	pr_warn_once("BCH_TRANSACTIONS_NR not big enough!");
+	return i;
+}
+
 void __bch2_trans_init(struct btree_trans *trans, struct bch_fs *c,
 		       unsigned expected_nr_iters,
 		       size_t expected_mem_bytes,
@@ -3262,19 +3278,11 @@ void __bch2_trans_init(struct btree_trans *trans, struct bch_fs *c,
 	trans->c		= c;
 	trans->fn		= fn;
 	trans->last_begin_time	= ktime_get_ns();
+	trans->fn_idx		= bch2_trans_get_fn_idx(trans, c, fn);
 	trans->task		= current;
 	trans->journal_replay_not_finished =
 		!test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags);
 
-	while (c->lock_held_stats.names[trans->lock_name_idx] != fn
-	       && c->lock_held_stats.names[trans->lock_name_idx] != 0)
-		trans->lock_name_idx++;
-
-	if (trans->lock_name_idx >= BCH_LOCK_TIME_NR)
-		pr_warn_once("lock_times array not big enough!");
-	else
-		c->lock_held_stats.names[trans->lock_name_idx] = fn;
-
 	bch2_trans_alloc_paths(trans, c);
 
 	if (expected_mem_bytes) {
@@ -3446,6 +3454,13 @@ void bch2_btree_trans_to_text(struct printbuf *out, struct btree_trans *trans)
 
 void bch2_fs_btree_iter_exit(struct bch_fs *c)
 {
+	struct btree_transaction_stats *s;
+
+	for (s = c->btree_transaction_stats;
+	     s < c->btree_transaction_stats + ARRAY_SIZE(c->btree_transaction_stats);
+	     s++)
+		bch2_time_stats_exit(&s->lock_hold_times);
+
 	if (c->btree_trans_barrier_initialized)
 		cleanup_srcu_struct(&c->btree_trans_barrier);
 	mempool_exit(&c->btree_trans_mem_pool);
@@ -3454,9 +3469,15 @@ void bch2_fs_btree_iter_exit(struct bch_fs *c)
 
 int bch2_fs_btree_iter_init(struct bch_fs *c)
 {
+	struct btree_transaction_stats *s;
 	unsigned nr = BTREE_ITER_MAX;
 	int ret;
 
+	for (s = c->btree_transaction_stats;
+	     s < c->btree_transaction_stats + ARRAY_SIZE(c->btree_transaction_stats);
+	     s++)
+		bch2_time_stats_init(&s->lock_hold_times);
+
 	INIT_LIST_HEAD(&c->btree_trans_list);
 	mutex_init(&c->btree_trans_lock);
 

fs/bcachefs/btree_locking.h

@@ -112,6 +112,26 @@ btree_lock_want(struct btree_path *path, int level)
 	return BTREE_NODE_UNLOCKED;
 }
 
+static inline struct btree_transaction_stats *btree_trans_stats(struct btree_trans *trans)
+{
+	return trans->fn_idx < ARRAY_SIZE(trans->c->btree_transaction_stats)
+		? &trans->c->btree_transaction_stats[trans->fn_idx]
+		: NULL;
+}
+
+static void btree_trans_lock_hold_time_update(struct btree_trans *trans,
+					      struct btree_path *path, unsigned level)
+{
+#ifdef CONFIG_BCACHEFS_LOCK_TIME_STATS
+	struct btree_transaction_stats *s = btree_trans_stats(trans);
+
+	if (s)
+		__bch2_time_stats_update(&s->lock_hold_times,
+					 path->l[level].lock_taken_time,
+					 ktime_get_ns());
+#endif
+}
+
 static inline void btree_node_unlock(struct btree_trans *trans,
 				     struct btree_path *path, unsigned level)
 {
@@ -121,15 +141,7 @@ static inline void btree_node_unlock(struct btree_trans *trans,
 
 	if (lock_type != BTREE_NODE_UNLOCKED) {
 		six_unlock_type(&path->l[level].b->c.lock, lock_type);
-#ifdef CONFIG_BCACHEFS_LOCK_TIME_STATS
-		if (trans->lock_name_idx < BCH_LOCK_TIME_NR) {
-			struct bch_fs *c = trans->c;
-
-			__bch2_time_stats_update(&c->lock_held_stats.times[trans->lock_name_idx],
-					       path->l[level].lock_taken_time,
-						 ktime_get_ns());
-		}
-#endif
+		btree_trans_lock_hold_time_update(trans, path, level);
 	}
 	mark_btree_node_unlocked(path, level);
 }

fs/bcachefs/btree_types.h

@@ -390,6 +390,7 @@ struct btree_trans {
 	struct task_struct	*task;
 	int			srcu_idx;
 
+	u8			fn_idx;
 	u8			nr_sorted;
 	u8			nr_updates;
 	bool			used_mempool:1;
@@ -431,7 +432,6 @@ struct btree_trans {
 	unsigned		journal_u64s;
 	unsigned		journal_preres_u64s;
 	struct replicas_delta_list *fs_usage_deltas;
-	int                      lock_name_idx;
 };
 
 #define BTREE_FLAGS()							\

fs/bcachefs/debug.c

@@ -653,14 +653,17 @@ static ssize_t lock_held_stats_read(struct file *file, char __user *buf,
 				      size_t size, loff_t *ppos)
 {
 	struct dump_iter        *i = file->private_data;
-	struct lock_held_stats *lhs = &i->c->lock_held_stats;
+	struct bch_fs *c = i->c;
 	int err;
 
 	i->ubuf = buf;
 	i->size = size;
 	i->ret  = 0;
 
-	while (lhs->names[i->iter] != 0 && i->iter < BCH_LOCK_TIME_NR) {
+	while (i->iter < ARRAY_SIZE(c->btree_transaction_fns) &&
+	       c->btree_transaction_fns[i->iter]) {
+		struct btree_transaction_stats *s = &c->btree_transaction_stats[i->iter];
+
 		err = flush_buf(i);
 		if (err)
 			return err;
@@ -668,11 +671,11 @@ static ssize_t lock_held_stats_read(struct file *file, char __user *buf,
 		if (!i->size)
 			break;
 
-		prt_printf(&i->buf, "%s:", lhs->names[i->iter]);
+		prt_printf(&i->buf, "%s: ", c->btree_transaction_fns[i->iter]);
 		prt_newline(&i->buf);
-		printbuf_indent_add(&i->buf, 8);
-		bch2_time_stats_to_text(&i->buf, &lhs->times[i->iter]);
-		printbuf_indent_sub(&i->buf, 8);
+		printbuf_indent_add(&i->buf, 2);
+		bch2_time_stats_to_text(&i->buf, &s->lock_hold_times);
+		printbuf_indent_sub(&i->buf, 2);
 		prt_newline(&i->buf);
 		i->iter++;
 	}
@@ -721,7 +724,7 @@ void bch2_fs_debug_init(struct bch_fs *c)
 			    c->btree_debug, &journal_pins_ops);
 
 	if (IS_ENABLED(CONFIG_BCACHEFS_LOCK_TIME_STATS)) {
-		debugfs_create_file("lock_held_stats", 0400, c->fs_debug_dir,
+		debugfs_create_file("btree_transaction_stats", 0400, c->fs_debug_dir,
 				c, &lock_held_stats_op);
 	}