rcu: Remove leg of force_quiescent_state() switch statement

The comparisons of rsp->gpnum nad rsp->completed in
rcu_process_dyntick() and force_quiescent_state() can be
replaced by the much more clear rcu_gp_in_progress() predicate
function.  After doing this, it becomes clear that the
RCU_SAVE_COMPLETED leg of the force_quiescent_state() function's
switch statement is almost completely a no-op.  A small change
to the RCU_SAVE_DYNTICK leg renders it a complete no-op, after
which it can be removed.  Doing so also eliminates the forcenow
local variable from force_quiescent_state().

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
LKML-Reference: <12626465501781-git-send-email->
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 2 insertions, 3 deletions

diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index 534856121b06..edb6fae0fa94 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -237,12 +237,11 @@ struct rcu_data {
 #define RCU_GP_IDLE             0       /* No grace period in progress. */
 #define RCU_GP_INIT             1       /* Grace period being initialized. */
 #define RCU_SAVE_DYNTICK        2       /* Need to scan dyntick state. */
-#define RCU_SAVE_COMPLETED      3       /* Need to save rsp->completed. */
-#define RCU_FORCE_QS            4       /* Need to force quiescent state. */
+#define RCU_FORCE_QS            3       /* Need to force quiescent state. */
 #ifdef CONFIG_NO_HZ
 #define RCU_SIGNAL_INIT         RCU_SAVE_DYNTICK
 #else /* #ifdef CONFIG_NO_HZ */
-#define RCU_SIGNAL_INIT         RCU_SAVE_COMPLETED
+#define RCU_SIGNAL_INIT         RCU_FORCE_QS
 #endif /* #else #ifdef CONFIG_NO_HZ */
 
 #define RCU_JIFFIES_TILL_FORCE_QS        3      /* for rsp->jiffies_force_qs */