From 59e836662860a28880d45b35e1fbc5afca4847ce Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Sun, 16 May 2021 21:17:27 -0700 Subject: rcutorture: Preempt rather than block when testing task stalls Currently, rcu_torture_stall() does a one-jiffy timed wait when stall_cpu_block is set. This works, but emits a pointless splat in CONFIG_PREEMPT=y kernels. This commit avoids this splat by instead invoking preempt_schedule() in CONFIG_PREEMPT=y kernels. This uses an admittedly ugly #ifdef, but abstracted approaches just looked worse. A prettier approach would provide a preempt_schedule() definition with a WARN_ON() for CONFIG_PREEMPT=n kernels, but this seems quite silly. Signed-off-by: Paul E. McKenney --- kernel/rcu/rcutorture.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'kernel/rcu') diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 40ef5417d954..ab4215266ebe 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -2022,8 +2022,13 @@ static int rcu_torture_stall(void *args) __func__, raw_smp_processor_id()); while (ULONG_CMP_LT((unsigned long)ktime_get_seconds(), stop_at)) - if (stall_cpu_block) + if (stall_cpu_block) { +#ifdef CONFIG_PREEMPTION + preempt_schedule(); +#else schedule_timeout_uninterruptible(HZ); +#endif + } if (stall_cpu_irqsoff) local_irq_enable(); else if (!stall_cpu_block) -- cgit v1.2.3-59-g8ed1b