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authorPaul E. McKenney <paulmck@kernel.org>2019-12-06 15:02:59 -0800
committerPaul E. McKenney <paulmck@kernel.org>2020-02-20 16:03:30 -0800
commit8171d3e0dafd37a9c833904e5a936f4154a1e95b (patch)
treebfa5aca794bbc74e1841e714d4245e487aa88920 /kernel/torture.c
parent4ab00bdd99a906c089b5c20ee7b5cb91e7c61123 (diff)
torture: Allow disabling of boottime CPU-hotplug torture operations
In theory, RCU-hotplug operations are supposed to work as soon as there is more than one CPU online. However, in practice, in normal production there is no way to make them happen until userspace is up and running. Besides which, on smaller systems, rcutorture doesn't start doing hotplug operations until 30 seconds after the start of boot, which on most systems also means the better part of 30 seconds after the end of boot. This commit therefore provides a new torture.disable_onoff_at_boot kernel boot parameter that suppresses CPU-hotplug torture operations until about the time that init is spawned. Of course, if you know of a need for boottime CPU-hotplug operations, then you should avoid passing this argument to any of the torture tests. You might also want to look at the splats linked to below. Link: https://lore.kernel.org/lkml/20191206185208.GA25636@paulmck-ThinkPad-P72/ Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/torture.c')
-rw-r--r--kernel/torture.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/torture.c b/kernel/torture.c
index e377b5b17de8..8683375dc0c7 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -42,6 +42,9 @@
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>");
+static bool disable_onoff_at_boot;
+module_param(disable_onoff_at_boot, bool, 0444);
+
static char *torture_type;
static int verbose;
@@ -229,6 +232,10 @@ torture_onoff(void *arg)
VERBOSE_TOROUT_STRING("torture_onoff end holdoff");
}
while (!torture_must_stop()) {
+ if (disable_onoff_at_boot && !rcu_inkernel_boot_has_ended()) {
+ schedule_timeout_interruptible(HZ / 10);
+ continue;
+ }
cpu = (torture_random(&rand) >> 4) % (maxcpu + 1);
if (!torture_offline(cpu,
&n_offline_attempts, &n_offline_successes,