rcu: Update rcutorture defaults

A number of new features have been added to rcutorture over the years, but
the defaults have not been updated to include them.  This commit therefore
turns on a couple of them that have proven helpful and trustworthy, namely
periodic progress reports and testing of NO_HZ.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

kernel/rcutorture.c

@@ -53,10 +53,11 @@ MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and Josh Triplett <josh@fre
 
 static int nreaders = -1;	/* # reader threads, defaults to 2*ncpus */
 static int nfakewriters = 4;	/* # fake writer threads */
-static int stat_interval;	/* Interval between stats, in seconds. */
-				/*  Defaults to "only at end of test". */
+static int stat_interval = 60;	/* Interval between stats, in seconds. */
+				/*  Zero means "only at end of test". */
 static bool verbose;		/* Print more debug info. */
-static bool test_no_idle_hz;	/* Test RCU's support for tickless idle CPUs. */
+static bool test_no_idle_hz = true;
+				/* Test RCU support for tickless idle CPUs. */
 static int shuffle_interval = 3; /* Interval between shuffles (in sec)*/
 static int stutter = 5;		/* Start/stop testing interval (in sec) */
 static int irqreader = 1;	/* RCU readers from irq (timers). */