[PATCH tip/core/rcu 1/9] rcu: Eliminate unused APIs intended for adaptive ticks

Paul E. McKenney
2013-08-18T01:50:03Z

From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

The rcu_user_enter_after_irq() and rcu_user_exit_after_irq()
functions were intended for use by adaptive ticks, but changes
in implementation have rendered them unnecessary. This commit
therefore removes them.

Reported-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
include/linux/rcupdate.h | 4 ----
kernel/rcutree.c | 43 -------------------------------------------
2 files changed, 47 deletions(-)

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 0c38abb..30bea9c 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -229,13 +229,9 @@ extern void rcu_irq_exit(void);
#ifdef CONFIG_RCU_USER_QS
extern void rcu_user_enter(void);
extern void rcu_user_exit(void);
-extern void rcu_user_enter_after_irq(void);
-extern void rcu_user_exit_after_irq(void);
#else
static inline void rcu_user_enter(void) { }
static inline void rcu_user_exit(void) { }
-static inline void rcu_user_enter_after_irq(void) { }
-static inline void rcu_user_exit_after_irq(void) { }
static inline void rcu_user_hooks_switch(struct task_struct *prev,
struct task_struct *next) { }
#endif /* CONFIG_RCU_USER_QS */
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 338f1d1..8807019 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -444,27 +444,6 @@ void rcu_user_enter(void)
{
rcu_eqs_enter(1);
}
-
-/**
- * rcu_user_enter_after_irq - inform RCU that we are going to resume userspace
- * after the current irq returns.
- *
- * This is similar to rcu_user_enter() but in the context of a non-nesting
- * irq. After this call, RCU enters into idle mode when the interrupt
- * returns.
- */
-void rcu_user_enter_after_irq(void)
-{
- unsigned long flags;
- struct rcu_dynticks *rdtp;
-
- local_irq_save(flags);
- rdtp = &__get_cpu_var(rcu_dynticks);
- /* Ensure this irq is interrupting a non-idle RCU state. */
- WARN_ON_ONCE(!(rdtp->dynticks_nesting & DYNTICK_TASK_MASK));
- rdtp->dynticks_nesting = 1;
- local_irq_restore(flags);
-}
#endif /* CONFIG_RCU_USER_QS */

/**
@@ -581,28 +560,6 @@ void rcu_user_exit(void)
{
rcu_eqs_exit(1);
}
-
-/**
- * rcu_user_exit_after_irq - inform RCU that we won't resume to userspace
- * idle mode after the current non-nesting irq returns.
- *
- * This is similar to rcu_user_exit() but in the context of an irq.
- * This is called when the irq has interrupted a userspace RCU idle mode
- * context. When the current non-nesting interrupt returns after this call,
- * the CPU won't restore the RCU idle mode.
- */
-void rcu_user_exit_after_irq(void)
-{
- unsigned long flags;
- struct rcu_dynticks *rdtp;
-
- local_irq_save(flags);
- rdtp = &__get_cpu_var(rcu_dynticks);
- /* Ensure we are interrupting an RCU idle mode. */
- WARN_ON_ONCE(rdtp->dynticks_nesting & DYNTICK_TASK_NEST_MASK);
- rdtp->dynticks_nesting += DYNTICK_TASK_EXIT_IDLE;
- local_irq_restore(flags);
-}
#endif /* CONFIG_RCU_USER_QS */

/**
--
1.8.1.5