[PATCH v2 3/6] locking/lockdep: Track number of zapped lock chains

Waiman Long
2019-12-16T15:16:00Z

Add a new counter nr_zapped_lock_chains to track the number lock chains
that have been removed.

Signed-off-by: Waiman Long <longman@redhat.com>
---
kernel/locking/lockdep.c | 2 ++
kernel/locking/lockdep_internals.h | 1 +
kernel/locking/lockdep_proc.c | 2 ++
3 files changed, 5 insertions(+)

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 30ebfe4978d5..8293f7e80ee6 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -2625,6 +2625,7 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next)
struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
static DECLARE_BITMAP(lock_chains_in_use, MAX_LOCKDEP_CHAINS);
static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];
+unsigned long nr_zapped_lock_chains;
unsigned int nr_chain_hlocks;

struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i)
@@ -4793,6 +4794,7 @@ static void remove_class_from_lock_chain(struct pending_free *pf,
*/
hlist_del_rcu(&chain->entry);
__set_bit(chain - lock_chains, pf->lock_chains_being_freed);
+ nr_zapped_lock_chains++;
#endif
}

diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h
index 5dec0fe12507..35758e469ff7 100644
--- a/kernel/locking/lockdep_internals.h
+++ b/kernel/locking/lockdep_internals.h
@@ -125,6 +125,7 @@ struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);

extern unsigned long nr_lock_classes;
extern unsigned long nr_zapped_classes;
+extern unsigned long nr_zapped_lock_chains;
extern unsigned long nr_list_entries;
long lockdep_next_lockchain(long i);
unsigned long lock_chain_count(void);
diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c
index 4c7dc0a8935d..7c15dd03cf49 100644
--- a/kernel/locking/lockdep_proc.c
+++ b/kernel/locking/lockdep_proc.c
@@ -345,6 +345,8 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
seq_puts(m, "\n");
seq_printf(m, " zapped classes: %11lu\n",
nr_zapped_classes);
+ seq_printf(m, " zapped lock chains: %11lu\n",
+ nr_zapped_lock_chains);
return 0;
}

--
2.18.1