diff options
Diffstat (limited to 'kernel/rcutree.c')
| -rw-r--r-- | kernel/rcutree.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 32618b3fe4e6..910d868808dc 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -671,6 +671,19 @@ int rcu_is_cpu_idle(void) } EXPORT_SYMBOL(rcu_is_cpu_idle); +/** + * __rcu_is_watching - are RCU read-side critical sections safe? + * + * Return true if RCU is watching the running CPU, which means that + * this CPU can safely enter RCU read-side critical sections. Unlike + * rcu_is_cpu_idle(), the caller of __rcu_is_watching() must have at + * least disabled preemption. + */ +bool __rcu_is_watching(void) +{ + return !!(atomic_read(this_cpu_ptr(&rcu_dynticks.dynticks)) & 0x1); +} + #if defined(CONFIG_PROVE_RCU) && defined(CONFIG_HOTPLUG_CPU) /* |
