rcu: Simplify RCU_TINY RCU callback invocation

TINY_PREEMPT_RCU could use a kthread to handle RCU callback invocation,
which required an API to abstract kthread vs. softirq invocation.
Now that TINY_PREEMPT_RCU is no longer with us, this commit retires
this API in favor of direct use of the relevant softirq primitives.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

3 files changed, 1 insertions, 5 deletions

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 70b1522badd3..257b50f9d2dc 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -216,6 +216,7 @@ static inline int rcu_preempt_depth(void)
 #endif /* #else #ifdef CONFIG_PREEMPT_RCU */
 
 /* Internal to kernel */
+extern void rcu_init(void);
 extern void rcu_sched_qs(int cpu);
 extern void rcu_bh_qs(int cpu);
 extern void rcu_check_callbacks(int cpu, int user);
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h
index d3c094ffa960..e756251b39bc 100644
--- a/include/linux/rcutiny.h
+++ b/include/linux/rcutiny.h
@@ -27,10 +27,6 @@
 
 #include <linux/cache.h>
 
-static inline void rcu_init(void)
-{
-}
-
 static inline void rcu_barrier_bh(void)
 {
         wait_rcu_gp(call_rcu_bh);
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index 952b79339304..3f1aa8f98666 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -30,7 +30,6 @@
 #ifndef __LINUX_RCUTREE_H
 #define __LINUX_RCUTREE_H
 
-extern void rcu_init(void);
 extern void rcu_note_context_switch(int cpu);
 extern int rcu_needs_cpu(int cpu, unsigned long *delta_jiffies);
 extern void rcu_cpu_stall_reset(void);