From 435508095ab5b6870e8140948983920ce4684e9b Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Wed, 4 Dec 2019 15:58:41 -0800 Subject: [PATCH] rcutorture: Refrain from callback flooding during boot Additional rcutorture aggression can result in, believe it or not, boot times in excess of three minutes on large hyperthreaded systems. This is long enough for rcutorture to decide to do some callback flooding, which seems a bit excessive given that userspace cannot have started until long after boot, and it is userspace that does the real-world callback flooding. Worse yet, because Tiny RCU lacks forward-progress functionality, the looping-in-the-kernel tests can also be problematic during early boot. This commit therefore causes rcutorture to hold off on callback flooding until about the time that init is spawned, and the same for looping-in-the-kernel tests for Tiny RCU. Signed-off-by: Paul E. McKenney --- kernel/rcu/rcutorture.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 9ba49788cb48..08fa4ef23914 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1994,8 +1994,11 @@ static int rcu_torture_fwd_prog(void *args) schedule_timeout_interruptible(fwd_progress_holdoff * HZ); WRITE_ONCE(rcu_fwd_emergency_stop, false); register_oom_notifier(&rcutorture_oom_nb); - rcu_torture_fwd_prog_nr(rfp, &tested, &tested_tries); - rcu_torture_fwd_prog_cr(rfp); + if (!IS_ENABLED(CONFIG_TINY_RCU) || + rcu_inkernel_boot_has_ended()) + rcu_torture_fwd_prog_nr(rfp, &tested, &tested_tries); + if (rcu_inkernel_boot_has_ended()) + rcu_torture_fwd_prog_cr(rfp); unregister_oom_notifier(&rcutorture_oom_nb); /* Avoid slow periods, better to test when busy. */