Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits)
  rcu: remove all rcu head initializations, except on_stack initializations
  rcu head introduce rcu head init on stack
  Debugobjects transition check
  rcu: fix build bug in RCU_FAST_NO_HZ builds
  rcu: RCU_FAST_NO_HZ must check RCU dyntick state
  rcu: make SRCU usable in modules
  rcu: improve the RCU CPU-stall warning documentation
  rcu: reduce the number of spurious RCU_SOFTIRQ invocations
  rcu: permit discontiguous cpu_possible_mask CPU numbering
  rcu: improve RCU CPU stall-warning messages
  rcu: print boot-time console messages if RCU configs out of ordinary
  rcu: disable CPU stall warnings upon panic
  rcu: enable CPU_STALL_VERBOSE by default
  rcu: slim down rcutiny by removing rcu_scheduler_active and friends
  rcu: refactor RCU's context-switch handling
  rcu: rename rcutiny rcu_ctrlblk to rcu_sched_ctrlblk
  rcu: shrink rcutiny by making synchronize_rcu_bh() be inline
  rcu: fix now-bogus rcu_scheduler_active comments.
  rcu: Fix bogus CONFIG_PROVE_LOCKING in comments to reflect reality.
  rcu: ignore offline CPUs in last non-dyntick-idle CPU check
  ...

2 files changed, 69 insertions, 4 deletions

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 935248bdbc47..930a9e5eae08 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -512,6 +512,18 @@ config PROVE_RCU
 
          Say N if you are unsure.
 
+config PROVE_RCU_REPEATEDLY
+        bool "RCU debugging: don't disable PROVE_RCU on first splat"
+        depends on PROVE_RCU
+        default n
+        help
+         By itself, PROVE_RCU will disable checking upon issuing the
+         first warning (or "splat").  This feature prevents such
+         disabling, allowing multiple RCU-lockdep warnings to be printed
+         on a single reboot.
+
+         Say N if you are unsure.
+
 config LOCKDEP
         bool
         depends on DEBUG_KERNEL && TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
@@ -793,7 +805,7 @@ config RCU_CPU_STALL_DETECTOR
 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
-        default n
+        default y
         help
           This option causes RCU to printk detailed per-task information
           for any tasks that are stalling the current RCU grace period.
diff --git a/lib/debugobjects.c b/lib/debugobjects.c
index bf007a43c053..deebcc57d4e6 100644
--- a/lib/debugobjects.c
+++ b/lib/debugobjects.c
@@ -141,6 +141,7 @@ alloc_object(void *addr, struct debug_bucket *b, struct debug_obj_descr *descr)
                 obj->object = addr;
                 obj->descr  = descr;
                 obj->state  = ODEBUG_STATE_NONE;
+                obj->astate = 0;
                 hlist_del(&obj->node);
 
                 hlist_add_head(&obj->node, &b->list);
@@ -252,8 +253,10 @@ static void debug_print_object(struct debug_obj *obj, char *msg)
 
         if (limit < 5 && obj->descr != descr_test) {
                 limit++;
-                WARN(1, KERN_ERR "ODEBUG: %s %s object type: %s\n", msg,
-                       obj_states[obj->state], obj->descr->name);
+                WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) "
+                                 "object type: %s\n",
+                        msg, obj_states[obj->state], obj->astate,
+                        obj->descr->name);
         }
         debug_objects_warnings++;
 }
@@ -447,7 +450,10 @@ void debug_object_deactivate(void *addr, struct debug_obj_descr *descr)
                 case ODEBUG_STATE_INIT:
                 case ODEBUG_STATE_INACTIVE:
                 case ODEBUG_STATE_ACTIVE:
-                        obj->state = ODEBUG_STATE_INACTIVE;
+                        if (!obj->astate)
+                                obj->state = ODEBUG_STATE_INACTIVE;
+                        else
+                                debug_print_object(obj, "deactivate");
                         break;
 
                 case ODEBUG_STATE_DESTROYED:
@@ -553,6 +559,53 @@ out_unlock:
         raw_spin_unlock_irqrestore(&db->lock, flags);
 }
 
+/**
+ * debug_object_active_state - debug checks object usage state machine
+ * @addr:       address of the object
+ * @descr:      pointer to an object specific debug description structure
+ * @expect:     expected state
+ * @next:       state to move to if expected state is found
+ */
+void
+debug_object_active_state(void *addr, struct debug_obj_descr *descr,
+                          unsigned int expect, unsigned int next)
+{
+        struct debug_bucket *db;
+        struct debug_obj *obj;
+        unsigned long flags;
+
+        if (!debug_objects_enabled)
+                return;
+
+        db = get_bucket((unsigned long) addr);
+
+        raw_spin_lock_irqsave(&db->lock, flags);
+
+        obj = lookup_object(addr, db);
+        if (obj) {
+                switch (obj->state) {
+                case ODEBUG_STATE_ACTIVE:
+                        if (obj->astate == expect)
+                                obj->astate = next;
+                        else
+                                debug_print_object(obj, "active_state");
+                        break;
+
+                default:
+                        debug_print_object(obj, "active_state");
+                        break;
+                }
+        } else {
+                struct debug_obj o = { .object = addr,
+                                       .state = ODEBUG_STATE_NOTAVAILABLE,
+                                       .descr = descr };
+
+                debug_print_object(&o, "active_state");
+        }
+
+        raw_spin_unlock_irqrestore(&db->lock, flags);
+}
+
 #ifdef CONFIG_DEBUG_OBJECTS_FREE
 static void __debug_check_no_obj_freed(const void *address, unsigned long size)
 {