rcu: Shrink ->dynticks_{nmi_,}nesting from long long to long

Because the ->dynticks_nesting field now only contains the process-based
nesting level instead of a value encoding both the process nesting level
and the irq "nesting" level, we no longer need a long long, even on
32-bit systems.  This commit therefore changes both the ->dynticks_nesting
and ->dynticks_nmi_nesting fields to long.

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

include/trace/events/rcu.h

@@ -436,14 +436,14 @@ TRACE_EVENT(rcu_fqs,
  */
 TRACE_EVENT(rcu_dyntick,
 
-	TP_PROTO(const char *polarity, long long oldnesting, long long newnesting),
+	TP_PROTO(const char *polarity, long oldnesting, long newnesting),
 
 	TP_ARGS(polarity, oldnesting, newnesting),
 
 	TP_STRUCT__entry(
 		__field(const char *, polarity)
-		__field(long long, oldnesting)
-		__field(long long, newnesting)
+		__field(long, oldnesting)
+		__field(long, newnesting)
 	),
 
 	TP_fast_assign(
@@ -452,7 +452,7 @@ TRACE_EVENT(rcu_dyntick,
 		__entry->newnesting = newnesting;
 	),
 
-	TP_printk("%s %llx %llx", __entry->polarity,
+	TP_printk("%s %lx %lx", __entry->polarity,
 		  __entry->oldnesting, __entry->newnesting)
 );
 

kernel/rcu/rcu.h

@@ -31,7 +31,7 @@
 #endif /* #else #ifdef CONFIG_RCU_TRACE */
 
 /* Offset to allow for unmatched rcu_irq_{enter,exit}(). */
-#define DYNTICK_IRQ_NONIDLE	((INT_MAX / 2) + 1)
+#define DYNTICK_IRQ_NONIDLE	((LONG_MAX / 2) + 1)
 
 
 /*

kernel/rcu/tree.c

@@ -946,7 +946,7 @@ void rcu_irq_exit_irqson(void)
  * we really have exited idle, and must do the appropriate accounting.
  * The caller must have disabled interrupts.
  */
-static void rcu_eqs_exit_common(long long newval, int user)
+static void rcu_eqs_exit_common(long newval, int user)
 {
 	RCU_TRACE(struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);)
 
@@ -979,7 +979,7 @@ static void rcu_eqs_exit_common(long long newval, int user)
 static void rcu_eqs_exit(bool user)
 {
 	struct rcu_dynticks *rdtp;
-	long long oldval;
+	long oldval;
 
 	lockdep_assert_irqs_disabled();
 	rdtp = this_cpu_ptr(&rcu_dynticks);
@@ -1043,7 +1043,7 @@ void rcu_user_exit(void)
 void rcu_nmi_enter(void)
 {
 	struct rcu_dynticks *rdtp = this_cpu_ptr(&rcu_dynticks);
-	int incby = 2;
+	long incby = 2;
 
 	/* Complain about underflow. */
 	WARN_ON_ONCE(rdtp->dynticks_nmi_nesting < 0);

kernel/rcu/tree.h

@@ -38,8 +38,8 @@
  * Dynticks per-CPU state.
  */
 struct rcu_dynticks {
-	long long dynticks_nesting; /* Track irq/process nesting level. */
-	int dynticks_nmi_nesting;   /* Track NMI nesting level. */
+	long dynticks_nesting;      /* Track process nesting level. */
+	long dynticks_nmi_nesting;  /* Track irq/NMI nesting level. */
 	atomic_t dynticks;	    /* Even value for idle, else odd. */
 	bool rcu_need_heavy_qs;     /* GP old, need heavy quiescent state. */
 	unsigned long rcu_qs_ctr;   /* Light universal quiescent state ctr. */

kernel/rcu/tree_plugin.h

@@ -1687,7 +1687,7 @@ static void print_cpu_stall_info(struct rcu_state *rsp, int cpu)
 	}
 	print_cpu_stall_fast_no_hz(fast_no_hz, cpu);
 	delta = rdp->mynode->gpnum - rdp->rcu_iw_gpnum;
-	pr_err("\t%d-%c%c%c%c: (%lu %s) idle=%03x/%llx/%d softirq=%u/%u fqs=%ld %s\n",
+	pr_err("\t%d-%c%c%c%c: (%lu %s) idle=%03x/%ld/%ld softirq=%u/%u fqs=%ld %s\n",
 	       cpu,
 	       "O."[!!cpu_online(cpu)],
 	       "o."[!!(rdp->grpmask & rdp->mynode->qsmaskinit)],