irq_enter()/exit() include the RCU handling. To properly separate the RCU handling provide variants which contain only the non-RCU related functionality.
Signed-off-by: Thomas Gleixner <t...@linutronix.de> --- include/linux/hardirq.h | 13 +++++++++++-- kernel/softirq.c | 35 +++++++++++++++++++++++++++-------- 2 files changed, 38 insertions(+), 10 deletions(-) --- a/include/linux/hardirq.h +++ b/include/linux/hardirq.h @@ -43,7 +43,11 @@ extern void rcu_nmi_exit(void); /* * Enter irq context (on NO_HZ, update jiffies): */ -extern void irq_enter(void); +void irq_enter(void); +/* + * Like irq_enter(), but RCU is already watching. + */ +void irq_enter_rcu(void); /* * Exit irq context without processing softirqs: @@ -58,7 +62,12 @@ extern void irq_enter(void); /* * Exit irq context and process softirqs if needed: */ -extern void irq_exit(void); +void irq_exit(void); + +/* + * Like irq_exit(), but return with RCU watching. + */ +void irq_exit_rcu(void); #ifndef arch_nmi_enter #define arch_nmi_enter() do { } while (0) --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -339,12 +339,11 @@ asmlinkage __visible void do_softirq(voi local_irq_restore(flags); } -/* - * Enter an interrupt context. +/** + * irq_enter_rcu - Enter an interrupt context with RCU watching */ -void irq_enter(void) +void irq_enter_rcu(void) { - rcu_irq_enter(); if (is_idle_task(current) && !in_interrupt()) { /* * Prevent raise_softirq from needlessly waking up ksoftirqd @@ -354,10 +353,18 @@ void irq_enter(void) tick_irq_enter(); _local_bh_enable(); } - __irq_enter(); } +/** + * irq_enter - Enter an interrupt context including RCU update + */ +void irq_enter(void) +{ + rcu_irq_enter(); + irq_enter_rcu(); +} + static inline void invoke_softirq(void) { if (ksoftirqd_running(local_softirq_pending())) @@ -397,10 +404,12 @@ static inline void tick_irq_exit(void) #endif } -/* - * Exit an interrupt context. Process softirqs if needed and possible: +/** + * irq_exit_rcu() - Exit an interrupt context without updating RCU + * + * Also processes softirqs if needed and possible. */ -void irq_exit(void) +void irq_exit_rcu(void) { #ifndef __ARCH_IRQ_EXIT_IRQS_DISABLED local_irq_disable(); @@ -413,6 +422,16 @@ void irq_exit(void) invoke_softirq(); tick_irq_exit(); +} + +/** + * irq_exit - Exit an interrupt context, update RCU and lockdep + * + * Also processes softirqs if needed and possible. + */ +void irq_exit(void) +{ + irq_exit_rcu(); rcu_irq_exit(); /* must be last! */ lockdep_hardirq_exit();