rcu: Clean up code based on review feedback from Josh Triplett, part 3

Whitespace fixes, updated comments, and trivial code movement.

o	Fix whitespace error in RCU_HEAD_INIT()

o	Move "So where is rcu_write_lock()" comment so that it does
	not come between the rcu_read_unlock() header comment and
	the rcu_read_unlock() definition.

o	Move the module_param statements for blimit, qhimark, and
	qlowmark to immediately follow the corresponding
	definitions.

o	In __rcu_offline_cpu(), move the assignment to rdp_me
	inside the "if" statement, given that rdp_me is not used
	outside of that "if" statement.
Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: akpm@linux-foundation.org
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: <12541491931164-git-send-email->
Signed-off-by: NIngo Molnar <mingo@elte.hu>

include/linux/rcupdate.h

@@ -77,7 +77,7 @@ extern int rcu_scheduler_active;
 #error "Unknown RCU implementation specified to kernel configuration"
 #endif
 
-#define RCU_HEAD_INIT 	{ .next = NULL, .func = NULL }
+#define RCU_HEAD_INIT	{ .next = NULL, .func = NULL }
 #define RCU_HEAD(head) struct rcu_head head = RCU_HEAD_INIT
 #define INIT_RCU_HEAD(ptr) do { \
        (ptr)->next = NULL; (ptr)->func = NULL; \
@@ -129,12 +129,6 @@ static inline void rcu_read_lock(void)
 	rcu_read_acquire();
 }
 
-/**
- * rcu_read_unlock - marks the end of an RCU read-side critical section.
- *
- * See rcu_read_lock() for more information.
- */
-
 /*
  * So where is rcu_write_lock()?  It does not exist, as there is no
  * way for writers to lock out RCU readers.  This is a feature, not
@@ -144,6 +138,12 @@ static inline void rcu_read_lock(void)
  * used as well.  RCU does not care how the writers keep out of each
  * others' way, as long as they do so.
  */
+
+/**
+ * rcu_read_unlock - marks the end of an RCU read-side critical section.
+ *
+ * See rcu_read_lock() for more information.
+ */
 static inline void rcu_read_unlock(void)
 {
 	rcu_read_release();

kernel/rcutree.c

@@ -122,6 +122,10 @@ static int blimit = 10;		/* Maximum callbacks per softirq. */
 static int qhimark = 10000;	/* If this many pending, ignore blimit. */
 static int qlowmark = 100;	/* Once only this many pending, use blimit. */
 
+module_param(blimit, int, 0);
+module_param(qhimark, int, 0);
+module_param(qlowmark, int, 0);
+
 static void force_quiescent_state(struct rcu_state *rsp, int relaxed);
 static int rcu_pending(int cpu);
 
@@ -878,8 +882,8 @@ static void __rcu_offline_cpu(int cpu, struct rcu_state *rsp)
 	 * indefinitely delay callbacks, you have far worse things to
 	 * be worrying about.
 	 */
-	rdp_me = rsp->rda[smp_processor_id()];
 	if (rdp->nxtlist != NULL) {
+		rdp_me = rsp->rda[smp_processor_id()];
 		*rdp_me->nxttail[RCU_NEXT_TAIL] = rdp->nxtlist;
 		rdp_me->nxttail[RCU_NEXT_TAIL] = rdp->nxttail[RCU_NEXT_TAIL];
 		rdp->nxtlist = NULL;
@@ -1575,7 +1579,3 @@ void __init __rcu_init(void)
 }
 
 #include "rcutree_plugin.h"
-
-module_param(blimit, int, 0);
-module_param(qhimark, int, 0);
-module_param(qlowmark, int, 0);