rcu: Simplify rcu_sched_qs() control flow

This commit applies an early-exit approach to rcu_sched_qs(), reducing
the nesting level and saving a line of code.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 23df266..ed3bc05 100644 (file)
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -244,22 +244,21 @@ void rcu_sched_qs(void)
 {
        unsigned long flags;
 
-       if (__this_cpu_read(rcu_sched_data.cpu_no_qs.s)) {
-               trace_rcu_grace_period(TPS("rcu_sched"),
-                                      __this_cpu_read(rcu_sched_data.gpnum),
-                                      TPS("cpuqs"));
-               __this_cpu_write(rcu_sched_data.cpu_no_qs.b.norm, false);
-               if (!__this_cpu_read(rcu_sched_data.cpu_no_qs.b.exp))
-                       return;
-               local_irq_save(flags);
-               if (__this_cpu_read(rcu_sched_data.cpu_no_qs.b.exp)) {
-                       __this_cpu_write(rcu_sched_data.cpu_no_qs.b.exp, false);
-                       rcu_report_exp_rdp(&rcu_sched_state,
-                                          this_cpu_ptr(&rcu_sched_data),
-                                          true);
-               }
-               local_irq_restore(flags);
+       if (!__this_cpu_read(rcu_sched_data.cpu_no_qs.s))
+               return;
+       trace_rcu_grace_period(TPS("rcu_sched"),
+                              __this_cpu_read(rcu_sched_data.gpnum),
+                              TPS("cpuqs"));
+       __this_cpu_write(rcu_sched_data.cpu_no_qs.b.norm, false);
+       if (!__this_cpu_read(rcu_sched_data.cpu_no_qs.b.exp))
+               return;
+       local_irq_save(flags);
+       if (__this_cpu_read(rcu_sched_data.cpu_no_qs.b.exp)) {
+               __this_cpu_write(rcu_sched_data.cpu_no_qs.b.exp, false);
+               rcu_report_exp_rdp(&rcu_sched_state,
+                                  this_cpu_ptr(&rcu_sched_data), true);
        }
+       local_irq_restore(flags);
 }
 
 void rcu_bh_qs(void)