bcache: add tracepoints for -EINTRy things

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

2 files changed, 73 insertions, 2 deletions

diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index c0968adc6b4b..301d311e2d16 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -444,6 +444,8 @@ static void do_btree_node_write(struct btree *b)
 		bch_submit_bbio_replicas(b->bio, b->c, &k.key, ptrs_to_write);
 		continue_at(cl, btree_node_write_done, NULL);
 	} else {
+		trace_bcache_btree_write_sync(b);
+
 		b->bio->bi_vcnt = 0;
 		bch_bio_map(b->bio, i);
 
@@ -1487,6 +1489,8 @@ static int btree_gc_coalesce(struct btree *b, struct btree_op *op,
 	return -EINTR;
 
 out_nocoalesce:
+	trace_bcache_btree_gc_coalesce_fail(b->c);
+
 	/* We may have written out some new nodes which are garbage now,
 	 * wait for writes to finish */
 	closure_sync(&cl);
@@ -1517,11 +1521,14 @@ static int btree_gc_rewrite_node(struct btree *b, struct btree_op *op,
 
 	/* recheck reserve after allocating replacement node */
 	if (btree_check_reserve(b, NULL)) {
+		trace_bcache_btree_gc_rewrite_node_fail(b);
 		btree_node_free(n);
 		rw_unlock(true, n);
 		return 0;
 	}
 
+	trace_bcache_btree_gc_rewrite_node(b);
+
 	bch_btree_node_write_sync(n);
 
 	bch_keylist_init(&keys);
@@ -2418,6 +2425,7 @@ int bch_btree_insert_node(struct btree *b, struct btree_op *op,
 		/* The first time this is called, we don't have a write lock
 		 * on the parent yet, so update op->lock and start again. */
 		if (op->lock <= btree_node_root(b)->level) {
+			trace_bcache_btree_upgrade_lock_fail(b, op);
 			op->lock = btree_node_root(b)->level + 1;
 			return -EINTR;
 		} else {
@@ -2458,9 +2466,12 @@ int bch_btree_insert_check_key(struct btree *b, struct btree_op *op,
 
 		if (b->key.val[0] != btree_ptr ||
 		    b->seq != seq + 1) {
+			trace_bcache_btree_upgrade_lock_fail(b, op);
 			op->lock = b->level;
 			goto out;
-               }
+		}
+
+		trace_bcache_btree_upgrade_lock(b, op);
 	}
 
 	bch_set_extent_ptrs(check_key, 1);
@@ -2617,8 +2628,10 @@ static int do_map_fn(struct btree *b, struct btree_op *op, struct bkey *from,
 	if (ret == MAP_CONTINUE)
 		*from = next;
 
-	if (ret == MAP_CONTINUE && op->iterator_invalidated)
+	if (ret == MAP_CONTINUE && op->iterator_invalidated) {
+		trace_bcache_btree_iterator_invalidated(b, op);
 		ret = -EINTR;
+	}
 
 	return ret;
 }
diff --git a/include/trace/events/bcache.h b/include/trace/events/bcache.h
index defd85ca1d4c..6ac900e71628 100644
--- a/include/trace/events/bcache.h
+++ b/include/trace/events/bcache.h
@@ -262,6 +262,11 @@ TRACE_EVENT(bcache_btree_write,
 		  __entry->bucket, __entry->block, __entry->keys)
 );
 
+DEFINE_EVENT(btree_node, bcache_btree_write_sync,
+	TP_PROTO(struct btree *b),
+	TP_ARGS(b)
+);
+
 DEFINE_EVENT(btree_node, bcache_btree_node_alloc,
 	TP_PROTO(struct btree *b),
 	TP_ARGS(b)
@@ -338,6 +343,44 @@ DEFINE_EVENT(cache_set, bcache_mca_cannibalize_unlock,
 	TP_ARGS(c)
 );
 
+DECLARE_EVENT_CLASS(btree_node_op,
+	TP_PROTO(struct btree *b, void *op),
+	TP_ARGS(b, op),
+
+	TP_STRUCT__entry(
+		__array(char,		uuid,	16		)
+		__field(size_t,		bucket			)
+		__field(enum btree_id,	id			)
+		__field(void *,		op			)
+	),
+
+	TP_fast_assign(
+		memcpy(__entry->uuid, b->c->sb.set_uuid.b, 16);
+		__entry->bucket	= PTR_BUCKET_NR(b->c, &b->key, 0);
+		__entry->id = b->btree_id;
+		__entry->op = op;
+	),
+
+	TP_printk("%pU bucket %zu id %u op %p", __entry->uuid, __entry->bucket,
+		__entry->id, __entry->op)
+);
+
+DEFINE_EVENT(btree_node_op, bcache_btree_upgrade_lock,
+	TP_PROTO(struct btree *b, void *op),
+	TP_ARGS(b, op)
+);
+
+DEFINE_EVENT(btree_node_op, bcache_btree_upgrade_lock_fail,
+	TP_PROTO(struct btree *b, void *op),
+	TP_ARGS(b, op)
+);
+
+DEFINE_EVENT(btree_node_op, bcache_btree_iterator_invalidated,
+	TP_PROTO(struct btree *b, void *op),
+	TP_ARGS(b, op)
+);
+
+
 /* Garbage collection */
 
 TRACE_EVENT(bcache_btree_gc_coalesce,
@@ -355,6 +398,21 @@ TRACE_EVENT(bcache_btree_gc_coalesce,
 	TP_printk("coalesced %u nodes", __entry->nodes)
 );
 
+DEFINE_EVENT(cache_set, bcache_btree_gc_coalesce_fail,
+	TP_PROTO(struct cache_set *c),
+	TP_ARGS(c)
+);
+
+DEFINE_EVENT(btree_node, bcache_btree_gc_rewrite_node,
+	TP_PROTO(struct btree *b),
+	TP_ARGS(b)
+);
+
+DEFINE_EVENT(btree_node, bcache_btree_gc_rewrite_node_fail,
+	TP_PROTO(struct btree *b),
+	TP_ARGS(b)
+);
+
 DEFINE_EVENT(cache_set, bcache_gc_start,
 	TP_PROTO(struct cache_set *c),
 	TP_ARGS(c)