Messages in this thread Patch in this message | | | From | "Paul E. McKenney" <> | Subject | [PATCH rcu 2/7] rcutorture: Preempt rather than block when testing task stalls | Date | Wed, 21 Jul 2021 14:04:36 -0700 |
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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 <paulmck@kernel.org> --- kernel/rcu/rcutorture.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 40ef5417d9545..ab4215266ebee 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) -- 2.31.1.189.g2e36527f23
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