squash! rcu: Refactor rcu_{nmi,irq}_{enter,exit}()
This commit also changes order of execution from this:
rcu_dynticks_task_exit();
rcu_dynticks_eqs_exit();
trace_rcu_dyntick();
rcu_cleanup_after_idle();
To this:
rcu_dynticks_task_exit();
rcu_dynticks_eqs_exit();
rcu_cleanup_after_idle();
trace_rcu_dyntick();
In other words, the calls to trace_rcu_dyntick() and trace_rcu_dyntick()
are reversed. This has no functional effect because the real
concern is whether a given call is before or after the call to
rcu_dynticks_eqs_exit(), and this patch does not change that. Before the
call to rcu_dynticks_eqs_exit(), RCU is not yet watching the current
CPU and after that call RCU is watching.
A similar switch in calling order happens on the idle-entry path, with
similar lack of effect for the same reasons.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 4ed74f1..6c5a7f0 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -774,6 +774,7 @@
/**
* rcu_nmi_exit_common - inform RCU of exit from NMI context
+ * @irq: Is this call from rcu_irq_exit?
*
* If we are returning from the outermost NMI handler that interrupted an
* RCU-idle period, update rdtp->dynticks and rdtp->dynticks_nmi_nesting
@@ -933,6 +934,7 @@
/**
* rcu_nmi_enter_common - inform RCU of entry to NMI context
+ * @irq: Is this call from rcu_irq_enter?
*
* If the CPU was idle from RCU's viewpoint, update rdtp->dynticks and
* rdtp->dynticks_nmi_nesting to let the RCU grace-period handling know
