From: Julia Cartwright <julia@xxxxxx> The forcing of an expedited grace period is an expensive and very RT-application unfriendly operation, as it forcibly preempts all running tasks on CPUs which are preventing the gp from expiring. By default, as a policy decision, disable the expediting of grace periods (after boot) on configurations which enable PREEMPT_RT. Suggested-by: Luiz Capitulino <lcapitulino@xxxxxxxxxx> Acked-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxx> Signed-off-by: Julia Cartwright <julia@xxxxxx> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> --- kernel/rcu/update.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 39334d2d2b379..b95ae86c40a7d 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -56,8 +56,10 @@ #ifndef CONFIG_TINY_RCU module_param(rcu_expedited, int, 0); module_param(rcu_normal, int, 0); -static int rcu_normal_after_boot; +static int rcu_normal_after_boot = IS_ENABLED(CONFIG_PREEMPT_RT); +#ifndef CONFIG_PREEMPT_RT module_param(rcu_normal_after_boot, int, 0); +#endif #endif /* #ifndef CONFIG_TINY_RCU */ #ifdef CONFIG_DEBUG_LOCK_ALLOC -- 2.29.2
