locking/lockdep: Introduce lockdep_next_lockchain() and lock_chain_count()

This patch does not change any functionality but makes the next patch in
this series easier to read.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Link: https://lkml.kernel.org/r/20190214230058.196511-14-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Bart Van Assche 2019-02-14 15:00:48 -08:00 committed by Ingo Molnar
parent ace35a7ac4
commit 2212684adf
3 changed files with 23 additions and 8 deletions

View File

@ -2096,7 +2096,7 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next)
return 0;
}
unsigned long nr_lock_chains;
static unsigned long nr_lock_chains;
struct lock_chain lock_chains[MAX_LOCKDEP_CHAINS];
int nr_chain_hlocks;
static u16 chain_hlocks[MAX_LOCKDEP_CHAIN_HLOCKS];
@ -2230,6 +2230,20 @@ static int check_no_collision(struct task_struct *curr,
return 1;
}
/*
* Given an index that is >= -1, return the index of the next lock chain.
* Return -2 if there is no next lock chain.
*/
long lockdep_next_lockchain(long i)
{
return i + 1 < nr_lock_chains ? i + 1 : -2;
}
unsigned long lock_chain_count(void)
{
return nr_lock_chains;
}
/*
* Adds a dependency chain into chain hashtable. And must be called with
* graph_lock held.

View File

@ -100,7 +100,8 @@ struct lock_class *lock_chain_get_class(struct lock_chain *chain, int i);
extern unsigned long nr_lock_classes;
extern unsigned long nr_list_entries;
extern unsigned long nr_lock_chains;
long lockdep_next_lockchain(long i);
unsigned long lock_chain_count(void);
extern int nr_chain_hlocks;
extern unsigned long nr_stack_trace_entries;

View File

@ -104,18 +104,18 @@ static const struct seq_operations lockdep_ops = {
#ifdef CONFIG_PROVE_LOCKING
static void *lc_start(struct seq_file *m, loff_t *pos)
{
if (*pos < 0)
return NULL;
if (*pos == 0)
return SEQ_START_TOKEN;
if (*pos - 1 < nr_lock_chains)
return lock_chains + (*pos - 1);
return NULL;
return lock_chains + (*pos - 1);
}
static void *lc_next(struct seq_file *m, void *v, loff_t *pos)
{
(*pos)++;
*pos = lockdep_next_lockchain(*pos - 1) + 1;
return lc_start(m, pos);
}
@ -268,7 +268,7 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
#ifdef CONFIG_PROVE_LOCKING
seq_printf(m, " dependency chains: %11lu [max: %lu]\n",
nr_lock_chains, MAX_LOCKDEP_CHAINS);
lock_chain_count(), MAX_LOCKDEP_CHAINS);
seq_printf(m, " dependency chain hlocks: %11d [max: %lu]\n",
nr_chain_hlocks, MAX_LOCKDEP_CHAIN_HLOCKS);
#endif