bcachefs: Optimize bch2_trans_init()

Now we store the transaction's fn idx in a local variable, instead of
redoing the lookup every time we call bch2_trans_init().

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/bcachefs.h b/fs/bcachefs/bcachefs.h
index 08fd899..7ca1aa3 100644 (file)
--- a/fs/bcachefs/bcachefs.h
+++ b/fs/bcachefs/bcachefs.h
@@ -929,7 +929,6 @@ mempool_t           bio_bounce_pages;
 
        struct bch2_time_stats  times[BCH_TIME_STAT_NR];
 
-       const char              *btree_transaction_fns[BCH_TRANSACTIONS_NR];
        struct btree_transaction_stats btree_transaction_stats[BCH_TRANSACTIONS_NR];
 };
 

diff --git a/fs/bcachefs/btree_iter.c b/fs/bcachefs/btree_iter.c
index 0bd6760..4402fce 100644 (file)
--- a/fs/bcachefs/btree_iter.c
+++ b/fs/bcachefs/btree_iter.c
@@ -2841,15 +2841,16 @@ 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)
+const char *bch2_btree_transaction_fns[BCH_TRANSACTIONS_NR];
+
+unsigned bch2_trans_get_fn_idx(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;
+       for (i = 0; i < ARRAY_SIZE(bch2_btree_transaction_fns); i++)
+               if (!bch2_btree_transaction_fns[i] ||
+                   bch2_btree_transaction_fns[i] == fn) {
+                       bch2_btree_transaction_fns[i] = fn;
                        return i;
                }
 
@@ -2857,16 +2858,17 @@ static inline unsigned bch2_trans_get_fn_idx(struct btree_trans *trans, struct b
        return i;
 }
 
-void __bch2_trans_init(struct btree_trans *trans, struct bch_fs *c, const char *fn)
+void __bch2_trans_init(struct btree_trans *trans, struct bch_fs *c, unsigned fn_idx)
        __acquires(&c->btree_trans_barrier)
 {
        struct btree_transaction_stats *s;
 
        memset(trans, 0, sizeof(*trans));
        trans->c                = c;
-       trans->fn               = fn;
+       trans->fn               = fn_idx < ARRAY_SIZE(bch2_btree_transaction_fns)
+               ? bch2_btree_transaction_fns[fn_idx] : NULL;
        trans->last_begin_time  = local_clock();
-       trans->fn_idx           = bch2_trans_get_fn_idx(trans, c, fn);
+       trans->fn_idx           = fn_idx;
        trans->locking_wait.task = current;
        trans->journal_replay_not_finished =
                !test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags);

diff --git a/fs/bcachefs/btree_iter.h b/fs/bcachefs/btree_iter.h
index 2e94cd2..cfbd07b 100644 (file)
--- a/fs/bcachefs/btree_iter.h
+++ b/fs/bcachefs/btree_iter.h
@@ -587,10 +587,21 @@ void bch2_btree_path_to_text(struct printbuf *, struct btree_path *);
 void bch2_trans_paths_to_text(struct printbuf *, struct btree_trans *);
 void bch2_dump_trans_updates(struct btree_trans *);
 void bch2_dump_trans_paths_updates(struct btree_trans *);
-void __bch2_trans_init(struct btree_trans *, struct bch_fs *, const char *);
+void __bch2_trans_init(struct btree_trans *, struct bch_fs *, unsigned);
 void bch2_trans_exit(struct btree_trans *);
 
-#define bch2_trans_init(_trans, _c, _nr_iters, _mem) __bch2_trans_init(_trans, _c, __func__)
+extern const char *bch2_btree_transaction_fns[BCH_TRANSACTIONS_NR];
+unsigned bch2_trans_get_fn_idx(const char *);
+
+#define bch2_trans_init(_trans, _c, _nr_iters, _mem)                   \
+do {                                                                   \
+       static unsigned trans_fn_idx;                                   \
+                                                                       \
+       if (unlikely(!trans_fn_idx))                                    \
+               trans_fn_idx = bch2_trans_get_fn_idx(__func__);         \
+                                                                       \
+       __bch2_trans_init(_trans, _c, trans_fn_idx);                    \
+} while (0)
 
 void bch2_btree_trans_to_text(struct printbuf *, struct btree_trans *);
 

diff --git a/fs/bcachefs/debug.c b/fs/bcachefs/debug.c
index 7abc707..a9e4180 100644 (file)
--- a/fs/bcachefs/debug.c
+++ b/fs/bcachefs/debug.c
@@ -638,11 +638,11 @@ static ssize_t lock_held_stats_read(struct file *file, char __user *buf,
                if (!i->size)
                        break;
 
-               if (i->iter == ARRAY_SIZE(c->btree_transaction_fns) ||
-                   !c->btree_transaction_fns[i->iter])
+               if (i->iter == ARRAY_SIZE(bch2_btree_transaction_fns) ||
+                   !bch2_btree_transaction_fns[i->iter])
                        break;
 
-               prt_printf(&i->buf, "%s: ", c->btree_transaction_fns[i->iter]);
+               prt_printf(&i->buf, "%s: ", bch2_btree_transaction_fns[i->iter]);
                prt_newline(&i->buf);
                printbuf_indent_add(&i->buf, 2);