diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 13 | ||||
| -rw-r--r-- | include/linux/rcupdate.h | 9 | ||||
| -rw-r--r-- | kernel/ksysfs.c | 4 | ||||
| -rw-r--r-- | kernel/rcu/update.c | 7 |
4 files changed, 24 insertions, 9 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 197305bbb9b7..d8186da15ca1 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -3308,20 +3308,23 @@ bytes respectively. Such letter suffixes can also be entirely omitted. of synchronize_rcu(). This reduces latency, but can increase CPU utilization, degrade real-time latency, and degrade energy efficiency. + No effect on CONFIG_TINY_RCU kernels. rcupdate.rcu_normal= [KNL] Use only normal grace-period primitives, for example, synchronize_rcu() instead of synchronize_rcu_expedited(). This improves - real-time latency, CPU utilization, and energy - efficiency, but can expose users to increased - grace-period latency. This parameter overrides - rcupdate.rcu_expedited. + real-time latency, CPU utilization, and + energy efficiency, but can expose users to + increased grace-period latency. This parameter + overrides rcupdate.rcu_expedited. No effect on + CONFIG_TINY_RCU kernels. rcupdate.rcu_normal_after_boot= [KNL] Once boot has completed (that is, after rcu_end_inkernel_boot() has been invoked), use - only normal grace-period primitives. + only normal grace-period primitives. No effect + on CONFIG_TINY_RCU kernels. rcupdate.rcu_task_stall_timeout= [KNL] Set timeout in jiffies for RCU task stall warning diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 98d9f30c02d4..47e95b80bebd 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -48,8 +48,10 @@ #include <asm/barrier.h> +#ifndef CONFIG_TINY_RCU extern int rcu_expedited; /* for sysctl */ extern int rcu_normal; /* also for sysctl */ +#endif /* #ifndef CONFIG_TINY_RCU */ #ifdef CONFIG_TINY_RCU /* Tiny RCU doesn't expedite, as its purpose in life is instead to be tiny. */ @@ -327,7 +329,6 @@ static inline int rcu_preempt_depth(void) /* Internal to kernel */ void rcu_init(void); -void rcu_end_inkernel_boot(void); void rcu_sched_qs(void); void rcu_bh_qs(void); void rcu_check_callbacks(int user); @@ -335,6 +336,12 @@ struct notifier_block; int rcu_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu); +#ifndef CONFIG_TINY_RCU +void rcu_end_inkernel_boot(void); +#else /* #ifndef CONFIG_TINY_RCU */ +static inline void rcu_end_inkernel_boot(void) { } +#endif /* #ifndef CONFIG_TINY_RCU */ + #ifdef CONFIG_RCU_STALL_COMMON void rcu_sysrq_start(void); void rcu_sysrq_end(void); diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c index b4e2fa52d8bc..152da4a48867 100644 --- a/kernel/ksysfs.c +++ b/kernel/ksysfs.c @@ -144,6 +144,7 @@ static ssize_t fscaps_show(struct kobject *kobj, } KERNEL_ATTR_RO(fscaps); +#ifndef CONFIG_TINY_RCU int rcu_expedited; static ssize_t rcu_expedited_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) @@ -177,6 +178,7 @@ static ssize_t rcu_normal_store(struct kobject *kobj, return count; } KERNEL_ATTR_RW(rcu_normal); +#endif /* #ifndef CONFIG_TINY_RCU */ /* * Make /sys/kernel/notes give the raw contents of our kernel .notes section. @@ -219,8 +221,10 @@ static struct attribute * kernel_attrs[] = { &kexec_crash_size_attr.attr, &vmcoreinfo_attr.attr, #endif +#ifndef CONFIG_TINY_RCU &rcu_expedited_attr.attr, &rcu_normal_attr.attr, +#endif NULL }; diff --git a/kernel/rcu/update.c b/kernel/rcu/update.c index 12b91f5a60a6..76b94e19430b 100644 --- a/kernel/rcu/update.c +++ b/kernel/rcu/update.c @@ -60,11 +60,12 @@ MODULE_ALIAS("rcupdate"); #endif #define MODULE_PARAM_PREFIX "rcupdate." +#ifndef CONFIG_TINY_RCU module_param(rcu_expedited, int, 0); module_param(rcu_normal, int, 0); - static int rcu_normal_after_boot; module_param(rcu_normal_after_boot, int, 0); +#endif /* #ifndef CONFIG_TINY_RCU */ #if defined(CONFIG_DEBUG_LOCK_ALLOC) && defined(CONFIG_PREEMPT_COUNT) /** @@ -172,8 +173,6 @@ void rcu_unexpedite_gp(void) } EXPORT_SYMBOL_GPL(rcu_unexpedite_gp); -#endif /* #ifndef CONFIG_TINY_RCU */ - /* * Inform RCU of the end of the in-kernel boot sequence. */ @@ -185,6 +184,8 @@ void rcu_end_inkernel_boot(void) WRITE_ONCE(rcu_normal, 1); } +#endif /* #ifndef CONFIG_TINY_RCU */ + #ifdef CONFIG_PREEMPT_RCU /* |