[PATCH tip/core/rcu 14/17] torture: Clean up after torture-test CPU hotplugging

paulmck
2021-01-06T17:18:53Z

This commit puts all CPUs back online at the end of a torture test,
and also unconditionally puts them online at the beginning of the test,
rather than just in the case of built-in tests. This allows torture tests
to behave in a predictable manner, whether built-in or based on modules.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
kernel/torture.c | 36 ++++++++++++++++++++++--------------
1 file changed, 22 insertions(+), 14 deletions(-)

diff --git a/kernel/torture.c b/kernel/torture.c
index 93eeeb2..507a20b 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -292,6 +292,26 @@ bool torture_online(int cpu, long *n_onl_attempts, long *n_onl_successes,
EXPORT_SYMBOL_GPL(torture_online);

/*
+ * Get everything online at the beginning and ends of tests.
+ */
+static void torture_online_all(char *phase)
+{
+ int cpu;
+ int ret;
+
+ for_each_possible_cpu(cpu) {
+ if (cpu_online(cpu))
+ continue;
+ ret = add_cpu(cpu);
+ if (ret && verbose) {
+ pr_alert("%s" TORTURE_FLAG
+ "%s: %s online %d: errno %d\n",
+ __func__, phase, torture_type, cpu, ret);
+ }
+ }
+}
+
+/*
* Execute random CPU-hotplug operations at the interval specified
* by the onoff_interval.
*/
@@ -301,25 +321,12 @@ torture_onoff(void *arg)
int cpu;
int maxcpu = -1;
DEFINE_TORTURE_RANDOM(rand);
- int ret;

VERBOSE_TOROUT_STRING("torture_onoff task started");
for_each_online_cpu(cpu)
maxcpu = cpu;
WARN_ON(maxcpu < 0);
- if (!IS_MODULE(CONFIG_TORTURE_TEST)) {
- for_each_possible_cpu(cpu) {
- if (cpu_online(cpu))
- continue;
- ret = add_cpu(cpu);
- if (ret && verbose) {
- pr_alert("%s" TORTURE_FLAG
- "%s: Initial online %d: errno %d\n",
- __func__, torture_type, cpu, ret);
- }
- }
- }
-
+ torture_online_all("Initial");
if (maxcpu == 0) {
VERBOSE_TOROUT_STRING("Only one CPU, so CPU-hotplug testing is disabled");
goto stop;
@@ -347,6 +354,7 @@ torture_onoff(void *arg)

stop:
torture_kthread_stopping("torture_onoff");
+ torture_online_all("Final");
return 0;
}

--
2.9.5