Since the backward dependencies are always empty, remove the locks_before field in lock_class struct and its occurrences.
Signed-off-by: Yuyang Du <[email protected]> --- include/linux/lockdep.h | 5 ++--- kernel/locking/lockdep.c | 15 +++------------ 2 files changed, 5 insertions(+), 15 deletions(-) diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 0e209b8..d0a587c 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -97,10 +97,9 @@ struct lock_class { /* * These fields represent a directed graph of lock dependencies, - * to every node we attach a list of "forward" and a list of - * "backward" graph nodes. + * to every node we attach a list of "forward" graph nodes. */ - struct list_head locks_after, locks_before; + struct list_head locks_after; struct lockdep_subclass_key *key; unsigned int subclass; diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index acaa3b3..fa6611e 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -823,8 +823,7 @@ static bool in_list(struct list_head *e, struct list_head *h) } /* - * Check whether entry @e occurs in any of the locks_after or locks_before - * lists. + * Check whether entry @e occurs in any of the locks_after list. */ static bool in_any_class_list(struct list_head *e) { @@ -833,8 +832,7 @@ static bool in_any_class_list(struct list_head *e) for (i = 0; i < ARRAY_SIZE(lock_classes); i++) { class = &lock_classes[i]; - if (in_list(e, &class->locks_after) || - in_list(e, &class->locks_before)) + if (in_list(e, &class->locks_after)) return true; } return false; @@ -922,8 +920,6 @@ static bool __check_data_structures(void) /* Check whether all classes have valid lock lists. */ for (i = 0; i < ARRAY_SIZE(lock_classes); i++) { class = &lock_classes[i]; - if (!class_lock_list_valid(class, &class->locks_before)) - return false; if (!class_lock_list_valid(class, &class->locks_after)) return false; } @@ -1021,7 +1017,6 @@ static void init_data_structures_once(void) for (i = 0; i < ARRAY_SIZE(lock_classes); i++) { list_add_tail(&lock_classes[i].lock_entry, &free_lock_classes); INIT_LIST_HEAD(&lock_classes[i].locks_after); - INIT_LIST_HEAD(&lock_classes[i].locks_before); } } @@ -1151,7 +1146,6 @@ static bool is_dynamic_key(const struct lock_class_key *key) class->key = key; class->name = lock->name; class->subclass = subclass; - WARN_ON_ONCE(!list_empty(&class->locks_before)); WARN_ON_ONCE(!list_empty(&class->locks_after)); class->name_version = count_matching_names(class); for (i = 0; i < ARRAY_SIZE(class->irqsafe_distance); i++) @@ -4798,8 +4792,7 @@ static void zap_class(struct pending_free *pf, struct lock_class *class) nr_list_entries--; list_del_rcu(&entry->entry); } - if (list_empty(&class->locks_after) && - list_empty(&class->locks_before)) { + if (list_empty(&class->locks_after)) { list_move_tail(&class->lock_entry, &pf->zapped); hlist_del_rcu(&class->hash_entry); WRITE_ONCE(class->key, NULL); @@ -4822,11 +4815,9 @@ static void reinit_class(struct lock_class *class) WARN_ON_ONCE(!class->lock_entry.next); WARN_ON_ONCE(!list_empty(&class->locks_after)); - WARN_ON_ONCE(!list_empty(&class->locks_before)); memset(p + offset, 0, sizeof(*class) - offset); WARN_ON_ONCE(!class->lock_entry.next); WARN_ON_ONCE(!list_empty(&class->locks_after)); - WARN_ON_ONCE(!list_empty(&class->locks_before)); } static inline int within(const void *addr, void *start, unsigned long size) -- 1.8.3.1
