So far so good, excellent work. On Fri, Aug 07, 2020 at 03:42:33PM +0800, Boqun Feng wrote: > @@ -371,6 +371,21 @@ static struct hlist_head classhash_table[CLASSHASH_SIZE]; > > static struct hlist_head chainhash_table[CHAINHASH_SIZE]; > > +/* > + * the id of held_lock > + */ > +static inline u16 hlock_id(struct held_lock *hlock) > +{ > + BUILD_BUG_ON(MAX_LOCKDEP_KEYS_BITS + 2 > 16); > + > + return (hlock->class_idx | (hlock->read << MAX_LOCKDEP_KEYS_BITS)); > +} > + > +static inline unsigned int chain_hlock_class_idx(u16 hlock_id) > +{ > + return hlock_id & MAX_LOCKDEP_KEYS; But did that want to be: return hlock_id & (MAX_LOCKDEP_KEYS-1); ? > +}