rcu: Remove conditional compilation for RCU CPU stall warnings

The RCU CPU stall warnings can now be controlled using the
rcu_cpu_stall_suppress boot-time parameter or via the same parameter
from sysfs.  There is therefore no longer any reason to have
kernel config parameters for this feature.  This commit therefore
removes the RCU_CPU_STALL_DETECTOR and RCU_CPU_STALL_DETECTOR_RUNNABLE
kernel config parameters.  The RCU_CPU_STALL_TIMEOUT parameter remains
to allow the timeout to be tuned and the RCU_CPU_STALL_VERBOSE parameter
remains to allow task-stall information to be suppressed if desired.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index c768bcd..93ce6de3 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -875,22 +875,9 @@
 	  Say N here if you want the RCU torture tests to start only
 	  after being manually enabled via /proc.
 
-config RCU_CPU_STALL_DETECTOR
-	bool "Check for stalled CPUs delaying RCU grace periods"
-	depends on TREE_RCU || TREE_PREEMPT_RCU
-	default y
-	help
-	  This option causes RCU to printk information on which
-	  CPUs are delaying the current grace period, but only when
-	  the grace period extends for excessive time periods.
-
-	  Say N if you want to disable such checks.
-
-	  Say Y if you are unsure.
-
 config RCU_CPU_STALL_TIMEOUT
 	int "RCU CPU stall timeout in seconds"
-	depends on RCU_CPU_STALL_DETECTOR
+	depends on TREE_RCU || TREE_PREEMPT_RCU
 	range 3 300
 	default 60
 	help
@@ -899,22 +886,9 @@
 	  RCU grace period persists, additional CPU stall warnings are
 	  printed at more widely spaced intervals.
 
-config RCU_CPU_STALL_DETECTOR_RUNNABLE
-	bool "RCU CPU stall checking starts automatically at boot"
-	depends on RCU_CPU_STALL_DETECTOR
-	default y
-	help
-	  If set, start checking for RCU CPU stalls immediately on
-	  boot.  Otherwise, RCU CPU stall checking must be manually
-	  enabled.
-
-	  Say Y if you are unsure.
-
-	  Say N if you wish to suppress RCU CPU stall checking during boot.
-
 config RCU_CPU_STALL_VERBOSE
 	bool "Print additional per-task information for RCU_CPU_STALL_DETECTOR"
-	depends on RCU_CPU_STALL_DETECTOR && TREE_PREEMPT_RCU
+	depends on TREE_PREEMPT_RCU
 	default y
 	help
 	  This option causes RCU to printk detailed per-task information