diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h index 3465ba704a111a764fc376d0753a0022c6f25c6e..980eb78751d9c20494f1c79222a05bac15a55f07 100644 --- a/include/linux/rcutiny.h +++ b/include/linux/rcutiny.h @@ -71,6 +71,7 @@ static inline void rcu_irq_enter(void) { } static inline void rcu_irq_exit_irqson(void) { } static inline void rcu_irq_enter_irqson(void) { } static inline void rcu_irq_exit(void) { } +static inline void rcu_irq_exit_preempt(void) { } static inline void exit_rcu(void) { } static inline bool rcu_preempt_need_deferred_qs(struct task_struct *t) { diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h index fbc26274af4d91dc672b7954123f8e2dd80a8591..02016e0aa8ebc1c69826be994829f833fedf95cd 100644 --- a/include/linux/rcutree.h +++ b/include/linux/rcutree.h @@ -47,6 +47,7 @@ void rcu_idle_enter(void); void rcu_idle_exit(void); void rcu_irq_enter(void); void rcu_irq_exit(void); +void rcu_irq_exit_preempt(void); void rcu_irq_enter_irqson(void); void rcu_irq_exit_irqson(void); diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 945401674b9d6c1f54ea6ee319f60e1ea2404670..62ee012993864448a6d81d86c30e6f3a05eeb0e9 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -743,6 +743,28 @@ void noinstr rcu_irq_exit(void) rcu_nmi_exit(); } +/** + * rcu_irq_exit_preempt - Inform RCU that current CPU is exiting irq + * towards in kernel preemption + * + * Same as rcu_irq_exit() but has a sanity check that scheduling is safe + * from RCU point of view. Invoked from return from interrupt before kernel + * preemption. + */ +void rcu_irq_exit_preempt(void) +{ + lockdep_assert_irqs_disabled(); + rcu_nmi_exit(); + + RCU_LOCKDEP_WARN(__this_cpu_read(rcu_data.dynticks_nesting) <= 0, + "RCU dynticks_nesting counter underflow/zero!"); + RCU_LOCKDEP_WARN(__this_cpu_read(rcu_data.dynticks_nmi_nesting) != + DYNTICK_IRQ_NONIDLE, + "Bad RCU dynticks_nmi_nesting counter\n"); + RCU_LOCKDEP_WARN(rcu_dynticks_curr_cpu_in_eqs(), + "RCU in extended quiescent state!"); +} + /* * Wrapper for rcu_irq_exit() where interrupts are enabled. *