Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core updates (RCU and locking) from Ingo Molnar:
 "Most of the diffstat comes from the RCU slow boot regression fixes,
  but there's also a debuggability improvements/fixes."

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  memblock: Document memblock_is_region_{memory,reserved}()
  rcu: Precompute RCU_FAST_NO_HZ timer offsets
  rcu: Move RCU_FAST_NO_HZ per-CPU variables to rcu_dynticks structure
  rcu: Update RCU_FAST_NO_HZ tracing for lazy callbacks
  rcu: RCU_FAST_NO_HZ detection of callback adoption
  spinlock: Indicate that a lockup is only suspected
  kdump: Execute kmsg_dump(KMSG_DUMP_PANIC) after smp_send_stop()
  panic: Make panic_on_oops configurable

lib/Kconfig.debug

@@ -241,6 +241,26 @@ config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
 	default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
 	default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
 
+config PANIC_ON_OOPS
+	bool "Panic on Oops" if EXPERT
+	default n
+	help
+	  Say Y here to enable the kernel to panic when it oopses. This
+	  has the same effect as setting oops=panic on the kernel command
+	  line.
+
+	  This feature is useful to ensure that the kernel does not do
+	  anything erroneous after an oops which could result in data
+	  corruption or other issues.
+
+	  Say N if unsure.
+
+config PANIC_ON_OOPS_VALUE
+	int
+	range 0 1
+	default 0 if !PANIC_ON_OOPS
+	default 1 if PANIC_ON_OOPS
+
 config DETECT_HUNG_TASK
 	bool "Detect Hung Tasks"
 	depends on DEBUG_KERNEL

lib/spinlock_debug.c

@@ -118,7 +118,7 @@ static void __spin_lock_debug(raw_spinlock_t *lock)
 		/* lockup suspected: */
 		if (print_once) {
 			print_once = 0;
-			spin_dump(lock, "lockup");
+			spin_dump(lock, "lockup suspected");
 #ifdef CONFIG_SMP
 			trigger_all_cpu_backtrace();
 #endif