Commit-ID: 13dbf9140c726c307a9c7e2b7ff83cf95da3bb44
Gitweb: http://git.kernel.org/tip/13dbf9140c726c307a9c7e2b7ff83cf95da3bb44
Author: Paul E. McKenney <paul.mckenney@xxxxxxxxxx>
AuthorDate: Mon, 23 Jul 2012 12:05:55 -0700
Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
CommitDate: Sun, 23 Sep 2012 07:42:22 -0700
rcu: Track CPU-hotplug duration statistics
Many rcutorture runs include CPU-hotplug operations in their stress
testing. This commit accumulates statistics on the durations of these
operations in deference to the recent concern about the overhead and
latency of these operations.
Signed-off-by: Paul E. McKenney <paul.mckenney@xxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Josh Triplett <josh@xxxxxxxxxxxxxxxx>
---
kernel/rcutorture.c | 42 +++++++++++++++++++++++++++++++++++++-----
1 files changed, 37 insertions(+), 5 deletions(-)
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 53c548c..2736cc8 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -177,8 +177,14 @@ static long n_rcu_torture_boosts;
static long n_rcu_torture_timers;
static long n_offline_attempts;
static long n_offline_successes;
+static unsigned long sum_offline;
+static int min_offline = -1;
+static int max_offline;
static long n_online_attempts;
static long n_online_successes;
+static unsigned long sum_online;
+static int min_online = -1;
+static int max_online;
static long n_barrier_attempts;
static long n_barrier_successes;
static struct list_head rcu_torture_removed;
@@ -1215,11 +1221,13 @@ rcu_torture_printk(char *page)
n_rcu_torture_boost_failure,
n_rcu_torture_boosts,
n_rcu_torture_timers);
- cnt += sprintf(&page[cnt], "onoff: %ld/%ld:%ld/%ld ",
- n_online_successes,
- n_online_attempts,
- n_offline_successes,
- n_offline_attempts);
+ cnt += sprintf(&page[cnt],
+ "onoff: %ld/%ld:%ld/%ld %d,%d:%d,%d %lu:%lu (HZ=%d) ",
+ n_online_successes, n_online_attempts,
+ n_offline_successes, n_offline_attempts,
+ min_online, max_online,
+ min_offline, max_offline,
+ sum_online, sum_offline, HZ);
cnt += sprintf(&page[cnt], "barrier: %ld/%ld:%ld",
n_barrier_successes,
n_barrier_attempts,
@@ -1491,8 +1499,10 @@ static int __cpuinit
rcu_torture_onoff(void *arg)
{
int cpu;
+ unsigned long delta;
int maxcpu = -1;
DEFINE_RCU_RANDOM(rand);
+ unsigned long starttime;
VERBOSE_PRINTK_STRING("rcu_torture_onoff task started");
for_each_online_cpu(cpu)
@@ -1510,6 +1520,7 @@ rcu_torture_onoff(void *arg)
printk(KERN_ALERT "%s" TORTURE_FLAG
"rcu_torture_onoff task: offlining %d\n",
torture_type, cpu);
+ starttime = jiffies;
n_offline_attempts++;
if (cpu_down(cpu) == 0) {
if (verbose)
@@ -1517,12 +1528,23 @@ rcu_torture_onoff(void *arg)
"rcu_torture_onoff task: offlined %d\n",
torture_type, cpu);
n_offline_successes++;
+ delta = jiffies - starttime;
+ sum_offline += delta;
+ if (min_offline < 0) {
+ min_offline = delta;
+ max_offline = delta;
+ }
+ if (min_offline > delta)
+ min_offline = delta;
+ if (max_offline < delta)
+ max_offline = delta;
}
} else if (cpu_is_hotpluggable(cpu)) {
if (verbose)
printk(KERN_ALERT "%s" TORTURE_FLAG
"rcu_torture_onoff task: onlining %d\n",
torture_type, cpu);
+ starttime = jiffies;
n_online_attempts++;
if (cpu_up(cpu) == 0) {
if (verbose)
@@ -1530,6 +1552,16 @@ rcu_torture_onoff(void *arg)
"rcu_torture_onoff task: onlined %d\n",
torture_type, cpu);
n_online_successes++;
+ delta = jiffies - starttime;
+ sum_online += delta;
+ if (min_online < 0) {
+ min_online = delta;
+ max_online = delta;
+ }
+ if (min_online > delta)
+ min_online = delta;
+ if (max_online < delta)
+ max_online = delta;
}
}
schedule_timeout_interruptible(onoff_interval * HZ);
--
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