torture: Reduce #ifdefs for preempt_schedule()

This commit adds a torture_preempt_schedule() that is nothingness
in !PREEMPT builds and is preempt_schedule() otherwise.  Then
torture_preempt_schedule() is used to eliminate several ugly #ifdefs,
both in rcutorture and in locktorture.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

include/linux/torture.h

@@ -96,4 +96,10 @@ void _torture_stop_kthread(char *m, struct task_struct **tp);
 #define torture_stop_kthread(n, tp) \
 	_torture_stop_kthread("Stopping " #n " task", &(tp))
 
+#ifdef CONFIG_PREEMPT
+#define torture_preempt_schedule() preempt_schedule()
+#else
+#define torture_preempt_schedule()
+#endif
+
 #endif /* __LINUX_TORTURE_H */

kernel/locking/locktorture.c

@@ -130,10 +130,8 @@ static void torture_lock_busted_write_delay(struct torture_random_state *trsp)
 	if (!(torture_random(trsp) %
 	      (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
 		mdelay(longdelay_ms);
-#ifdef CONFIG_PREEMPT
 	if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
-		preempt_schedule();  /* Allow test to be preempted. */
-#endif
+		torture_preempt_schedule();  /* Allow test to be preempted. */
 }
 
 static void torture_lock_busted_write_unlock(void)
@@ -179,10 +177,8 @@ static void torture_spin_lock_write_delay(struct torture_random_state *trsp)
 	if (!(torture_random(trsp) %
 	      (cxt.nrealwriters_stress * 2 * shortdelay_us)))
 		udelay(shortdelay_us);
-#ifdef CONFIG_PREEMPT
 	if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
-		preempt_schedule();  /* Allow test to be preempted. */
-#endif
+		torture_preempt_schedule();  /* Allow test to be preempted. */
 }
 
 static void torture_spin_lock_write_unlock(void) __releases(torture_spinlock)
@@ -352,10 +348,8 @@ static void torture_mutex_delay(struct torture_random_state *trsp)
 		mdelay(longdelay_ms * 5);
 	else
 		mdelay(longdelay_ms / 5);
-#ifdef CONFIG_PREEMPT
 	if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
-		preempt_schedule();  /* Allow test to be preempted. */
-#endif
+		torture_preempt_schedule();  /* Allow test to be preempted. */
 }
 
 static void torture_mutex_unlock(void) __releases(torture_mutex)
@@ -507,10 +501,8 @@ static void torture_rtmutex_delay(struct torture_random_state *trsp)
 	if (!(torture_random(trsp) %
 	      (cxt.nrealwriters_stress * 2 * shortdelay_us)))
 		udelay(shortdelay_us);
-#ifdef CONFIG_PREEMPT
 	if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
-		preempt_schedule();  /* Allow test to be preempted. */
-#endif
+		torture_preempt_schedule();  /* Allow test to be preempted. */
 }
 
 static void torture_rtmutex_unlock(void) __releases(torture_rtmutex)
@@ -547,10 +539,8 @@ static void torture_rwsem_write_delay(struct torture_random_state *trsp)
 		mdelay(longdelay_ms * 10);
 	else
 		mdelay(longdelay_ms / 10);
-#ifdef CONFIG_PREEMPT
 	if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
-		preempt_schedule();  /* Allow test to be preempted. */
-#endif
+		torture_preempt_schedule();  /* Allow test to be preempted. */
 }
 
 static void torture_rwsem_up_write(void) __releases(torture_rwsem)
@@ -574,10 +564,8 @@ static void torture_rwsem_read_delay(struct torture_random_state *trsp)
 		mdelay(longdelay_ms * 2);
 	else
 		mdelay(longdelay_ms / 2);
-#ifdef CONFIG_PREEMPT
 	if (!(torture_random(trsp) % (cxt.nrealreaders_stress * 20000)))
-		preempt_schedule();  /* Allow test to be preempted. */
-#endif
+		torture_preempt_schedule();  /* Allow test to be preempted. */
 }
 
 static void torture_rwsem_up_read(void) __releases(torture_rwsem)

kernel/rcu/rcutorture.c

@@ -315,11 +315,9 @@ static void rcu_read_delay(struct torture_random_state *rrsp)
 	}
 	if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us)))
 		udelay(shortdelay_us);
-#ifdef CONFIG_PREEMPT
 	if (!preempt_count() &&
 	    !(torture_random(rrsp) % (nrealreaders * 20000)))
-		preempt_schedule();  /* No QS if preempt_disable() in effect */
-#endif
+		torture_preempt_schedule();  /* QS only if preemptible. */
 }
 
 static void rcu_torture_read_unlock(int idx) __releases(RCU)