lockstat: contend with points
We currently only provide points that have to wait on contention, also
lists the points we have to wait for.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index dbda475..234a9dc 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -136,16 +136,16 @@
#ifdef CONFIG_LOCK_STAT
static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], lock_stats);
-static int lock_contention_point(struct lock_class *class, unsigned long ip)
+static int lock_point(unsigned long points[], unsigned long ip)
{
int i;
- for (i = 0; i < ARRAY_SIZE(class->contention_point); i++) {
- if (class->contention_point[i] == 0) {
- class->contention_point[i] = ip;
+ for (i = 0; i < LOCKSTAT_POINTS; i++) {
+ if (points[i] == 0) {
+ points[i] = ip;
break;
}
- if (class->contention_point[i] == ip)
+ if (points[i] == ip)
break;
}
@@ -185,6 +185,9 @@
for (i = 0; i < ARRAY_SIZE(stats.contention_point); i++)
stats.contention_point[i] += pcs->contention_point[i];
+ for (i = 0; i < ARRAY_SIZE(stats.contending_point); i++)
+ stats.contending_point[i] += pcs->contending_point[i];
+
lock_time_add(&pcs->read_waittime, &stats.read_waittime);
lock_time_add(&pcs->write_waittime, &stats.write_waittime);
@@ -209,6 +212,7 @@
memset(cpu_stats, 0, sizeof(struct lock_class_stats));
}
memset(class->contention_point, 0, sizeof(class->contention_point));
+ memset(class->contending_point, 0, sizeof(class->contending_point));
}
static struct lock_class_stats *get_lock_stats(struct lock_class *class)
@@ -3001,7 +3005,7 @@
struct held_lock *hlock, *prev_hlock;
struct lock_class_stats *stats;
unsigned int depth;
- int i, point;
+ int i, contention_point, contending_point;
depth = curr->lockdep_depth;
if (DEBUG_LOCKS_WARN_ON(!depth))
@@ -3025,18 +3029,22 @@
found_it:
hlock->waittime_stamp = sched_clock();
- point = lock_contention_point(hlock_class(hlock), ip);
+ contention_point = lock_point(hlock_class(hlock)->contention_point, ip);
+ contending_point = lock_point(hlock_class(hlock)->contending_point,
+ lock->ip);
stats = get_lock_stats(hlock_class(hlock));
- if (point < ARRAY_SIZE(stats->contention_point))
- stats->contention_point[point]++;
+ if (contention_point < LOCKSTAT_POINTS)
+ stats->contention_point[contention_point]++;
+ if (contending_point < LOCKSTAT_POINTS)
+ stats->contending_point[contending_point]++;
if (lock->cpu != smp_processor_id())
stats->bounces[bounce_contended + !!hlock->read]++;
put_lock_stats(stats);
}
static void
-__lock_acquired(struct lockdep_map *lock)
+__lock_acquired(struct lockdep_map *lock, unsigned long ip)
{
struct task_struct *curr = current;
struct held_lock *hlock, *prev_hlock;
@@ -3085,6 +3093,7 @@
put_lock_stats(stats);
lock->cpu = cpu;
+ lock->ip = ip;
}
void lock_contended(struct lockdep_map *lock, unsigned long ip)
@@ -3106,7 +3115,7 @@
}
EXPORT_SYMBOL_GPL(lock_contended);
-void lock_acquired(struct lockdep_map *lock)
+void lock_acquired(struct lockdep_map *lock, unsigned long ip)
{
unsigned long flags;
@@ -3119,7 +3128,7 @@
raw_local_irq_save(flags);
check_flags(flags);
current->lockdep_recursion = 1;
- __lock_acquired(lock);
+ __lock_acquired(lock, ip);
current->lockdep_recursion = 0;
raw_local_irq_restore(flags);
}
diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c
index 8d3a6eba..13716b8 100644
--- a/kernel/lockdep_proc.c
+++ b/kernel/lockdep_proc.c
@@ -557,7 +557,7 @@
if (stats->read_holdtime.nr)
namelen += 2;
- for (i = 0; i < ARRAY_SIZE(class->contention_point); i++) {
+ for (i = 0; i < LOCKSTAT_POINTS; i++) {
char sym[KSYM_SYMBOL_LEN];
char ip[32];
@@ -574,6 +574,23 @@
stats->contention_point[i],
ip, sym);
}
+ for (i = 0; i < LOCKSTAT_POINTS; i++) {
+ char sym[KSYM_SYMBOL_LEN];
+ char ip[32];
+
+ if (class->contending_point[i] == 0)
+ break;
+
+ if (!i)
+ seq_line(m, '-', 40-namelen, namelen);
+
+ sprint_symbol(sym, class->contending_point[i]);
+ snprintf(ip, sizeof(ip), "[<%p>]",
+ (void *)class->contending_point[i]);
+ seq_printf(m, "%40s %14lu %29s %s\n", name,
+ stats->contending_point[i],
+ ip, sym);
+ }
if (i) {
seq_puts(m, "\n");
seq_line(m, '.', 0, 40 + 1 + 10 * (14 + 1));
@@ -583,7 +600,7 @@
static void seq_header(struct seq_file *m)
{
- seq_printf(m, "lock_stat version 0.2\n");
+ seq_printf(m, "lock_stat version 0.3\n");
seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s "
"%14s %14s\n",
diff --git a/kernel/mutex.c b/kernel/mutex.c
index 12c779dc..39a3816 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -184,7 +184,7 @@
}
done:
- lock_acquired(&lock->dep_map);
+ lock_acquired(&lock->dep_map, ip);
/* got the lock - rejoice! */
mutex_remove_waiter(lock, &waiter, task_thread_info(task));
debug_mutex_set_owner(lock, task_thread_info(task));
