[PATCH tip/core/rcu 13/17] rcu: Fold rcu_eqs_enter_common() into rcu_eqs_enter()

From: Paul E. McKenney
Date: Fri Dec 01 2017 - 14:37:27 EST


There is now only one call to rcu_eqs_enter_common() and there is no other
reason to keep it separate. This commit therefore inlines it into its
sole call site, saving a few lines of code in the process.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
kernel/rcu/tree.c | 43 ++++++++++++++++---------------------------
1 file changed, 16 insertions(+), 27 deletions(-)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index b2ded4d436c6..5c8a5796c71f 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -749,16 +749,27 @@ cpu_needs_another_gp(struct rcu_state *rsp, struct rcu_data *rdp)
}

/*
- * rcu_eqs_enter_common - current CPU is entering an extended quiescent state
+ * Enter an RCU extended quiescent state, which can be either the
+ * idle loop or adaptive-tickless usermode execution.
*
- * Enter idle, doing appropriate accounting. The caller must have
- * disabled interrupts.
+ * We crowbar the ->dynticks_nmi_nesting field to zero to allow for
+ * the possibility of usermode upcalls having messed up our count
+ * of interrupt nesting level during the prior busy period.
*/
-static void rcu_eqs_enter_common(bool user)
+static void rcu_eqs_enter(bool user)
{
struct rcu_state *rsp;
struct rcu_data *rdp;
- struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
+ struct rcu_dynticks *rdtp;
+
+ rdtp = this_cpu_ptr(&rcu_dynticks);
+ WRITE_ONCE(rdtp->dynticks_nmi_nesting, 0);
+ WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) &&
+ rdtp->dynticks_nesting == 0);
+ if (rdtp->dynticks_nesting != 1) {
+ rdtp->dynticks_nesting--;
+ return;
+ }

lockdep_assert_irqs_disabled();
trace_rcu_dyntick(TPS("Start"), rdtp->dynticks_nesting, 0, rdtp->dynticks);
@@ -783,28 +794,6 @@ static void rcu_eqs_enter_common(bool user)
rcu_dynticks_task_enter();
}

-/*
- * Enter an RCU extended quiescent state, which can be either the
- * idle loop or adaptive-tickless usermode execution.
- *
- * We crowbar the ->dynticks_nmi_nesting field to zero to allow for
- * the possibility of usermode upcalls having messed up our count
- * of interrupt nesting level during the prior busy period.
- */
-static void rcu_eqs_enter(bool user)
-{
- struct rcu_dynticks *rdtp;
-
- rdtp = this_cpu_ptr(&rcu_dynticks);
- WRITE_ONCE(rdtp->dynticks_nmi_nesting, 0);
- WARN_ON_ONCE(IS_ENABLED(CONFIG_RCU_EQS_DEBUG) &&
- rdtp->dynticks_nesting == 0);
- if (rdtp->dynticks_nesting == 1)
- rcu_eqs_enter_common(user);
- else
- rdtp->dynticks_nesting--;
-}
-
/**
* rcu_idle_enter - inform RCU that current CPU is entering idle
*
--
2.5.2