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

* 'locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  lockdep: add stack dumps to asserts
  hrtimer: fix rq->lock inversion (again)

6 files changed, 57 insertions, 25 deletions

diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index bd37078c2d7d..0d2f7c8a33d6 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -336,6 +336,11 @@ extern int hrtimer_start(struct hrtimer *timer, ktime_t tim,
                          const enum hrtimer_mode mode);
 extern int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
                         unsigned long range_ns, const enum hrtimer_mode mode);
+extern int
+__hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
+                         unsigned long delta_ns,
+                         const enum hrtimer_mode mode, int wakeup);
+
 extern int hrtimer_cancel(struct hrtimer *timer);
 extern int hrtimer_try_to_cancel(struct hrtimer *timer);
 
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index ce2c07d99fc3..8a9613d0c674 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -299,6 +299,7 @@ extern void softirq_init(void);
 #define __raise_softirq_irqoff(nr) do { or_softirq_pending(1UL << (nr)); } while (0)
 extern void raise_softirq_irqoff(unsigned int nr);
 extern void raise_softirq(unsigned int nr);
+extern void wakeup_softirqd(void);
 
 /* This is the worklist that queues up per-cpu softirq work.
  *
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index f394d2a42ca3..cb8a15c19583 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -651,14 +651,20 @@ static inline void hrtimer_init_timer_hres(struct hrtimer *timer)
  * and expiry check is done in the hrtimer_interrupt or in the softirq.
  */
 static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
-                                            struct hrtimer_clock_base *base)
+                                            struct hrtimer_clock_base *base,
+                                            int wakeup)
 {
         if (base->cpu_base->hres_active && hrtimer_reprogram(timer, base)) {
-                spin_unlock(&base->cpu_base->lock);
-                raise_softirq_irqoff(HRTIMER_SOFTIRQ);
-                spin_lock(&base->cpu_base->lock);
+                if (wakeup) {
+                        spin_unlock(&base->cpu_base->lock);
+                        raise_softirq_irqoff(HRTIMER_SOFTIRQ);
+                        spin_lock(&base->cpu_base->lock);
+                } else
+                        __raise_softirq_irqoff(HRTIMER_SOFTIRQ);
+
                 return 1;
         }
+
         return 0;
 }
 
@@ -703,7 +709,8 @@ static inline int hrtimer_is_hres_enabled(void) { return 0; }
 static inline int hrtimer_switch_to_hres(void) { return 0; }
 static inline void hrtimer_force_reprogram(struct hrtimer_cpu_base *base) { }
 static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
-                                            struct hrtimer_clock_base *base)
+                                            struct hrtimer_clock_base *base,
+                                            int wakeup)
 {
         return 0;
 }
@@ -886,20 +893,9 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_clock_base *base)
         return 0;
 }
 
-/**
- * hrtimer_start_range_ns - (re)start an hrtimer on the current CPU
- * @timer:      the timer to be added
- * @tim:        expiry time
- * @delta_ns:   "slack" range for the timer
- * @mode:       expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL)
- *
- * Returns:
- *  0 on success
- *  1 when the timer was active
- */
-int
-hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, unsigned long delta_ns,
-                        const enum hrtimer_mode mode)
+int __hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
+                unsigned long delta_ns, const enum hrtimer_mode mode,
+                int wakeup)
 {
         struct hrtimer_clock_base *base, *new_base;
         unsigned long flags;
@@ -940,12 +936,29 @@ hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim, unsigned long delta_n
          * XXX send_remote_softirq() ?
          */
         if (leftmost && new_base->cpu_base == &__get_cpu_var(hrtimer_bases))
-                hrtimer_enqueue_reprogram(timer, new_base);
+                hrtimer_enqueue_reprogram(timer, new_base, wakeup);
 
         unlock_hrtimer_base(timer, &flags);
 
         return ret;
 }
+
+/**
+ * hrtimer_start_range_ns - (re)start an hrtimer on the current CPU
+ * @timer:      the timer to be added
+ * @tim:        expiry time
+ * @delta_ns:   "slack" range for the timer
+ * @mode:       expiry mode: absolute (HRTIMER_ABS) or relative (HRTIMER_REL)
+ *
+ * Returns:
+ *  0 on success
+ *  1 when the timer was active
+ */
+int hrtimer_start_range_ns(struct hrtimer *timer, ktime_t tim,
+                unsigned long delta_ns, const enum hrtimer_mode mode)
+{
+        return __hrtimer_start_range_ns(timer, tim, delta_ns, mode, 1);
+}
 EXPORT_SYMBOL_GPL(hrtimer_start_range_ns);
 
 /**
@@ -961,7 +974,7 @@ EXPORT_SYMBOL_GPL(hrtimer_start_range_ns);
 int
 hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
 {
-        return hrtimer_start_range_ns(timer, tim, 0, mode);
+        return __hrtimer_start_range_ns(timer, tim, 0, mode, 1);
 }
 EXPORT_SYMBOL_GPL(hrtimer_start);
 
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 81b5f33970b8..b0f011866969 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -793,6 +793,7 @@ register_lock_class(struct lockdep_map *lock, unsigned int subclass, int force)
 
                 printk("BUG: MAX_LOCKDEP_KEYS too low!\n");
                 printk("turning off the locking correctness validator.\n");
+                dump_stack();
                 return NULL;
         }
         class = lock_classes + nr_lock_classes++;
@@ -856,6 +857,7 @@ static struct lock_list *alloc_list_entry(void)
 
                 printk("BUG: MAX_LOCKDEP_ENTRIES too low!\n");
                 printk("turning off the locking correctness validator.\n");
+                dump_stack();
                 return NULL;
         }
         return list_entries + nr_list_entries++;
@@ -1682,6 +1684,7 @@ cache_hit:
 
                 printk("BUG: MAX_LOCKDEP_CHAINS too low!\n");
                 printk("turning off the locking correctness validator.\n");
+                dump_stack();
                 return 0;
         }
         chain = lock_chains + nr_lock_chains++;
@@ -2541,6 +2544,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
                 debug_locks_off();
                 printk("BUG: MAX_LOCKDEP_SUBCLASSES too low!\n");
                 printk("turning off the locking correctness validator.\n");
+                dump_stack();
                 return 0;
         }
 
@@ -2637,6 +2641,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
                 debug_locks_off();
                 printk("BUG: MAX_LOCK_DEPTH too low!\n");
                 printk("turning off the locking correctness validator.\n");
+                dump_stack();
                 return 0;
         }
 
diff --git a/kernel/sched.c b/kernel/sched.c
index bec249885e17..6cc1fd5d5072 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -231,13 +231,20 @@ static void start_rt_bandwidth(struct rt_bandwidth *rt_b)
 
         spin_lock(&rt_b->rt_runtime_lock);
         for (;;) {
+                unsigned long delta;
+                ktime_t soft, hard;
+
                 if (hrtimer_active(&rt_b->rt_period_timer))
                         break;
 
                 now = hrtimer_cb_get_time(&rt_b->rt_period_timer);
                 hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period);
-                hrtimer_start_expires(&rt_b->rt_period_timer,
-                                HRTIMER_MODE_ABS);
+
+                soft = hrtimer_get_softexpires(&rt_b->rt_period_timer);
+                hard = hrtimer_get_expires(&rt_b->rt_period_timer);
+                delta = ktime_to_ns(ktime_sub(hard, soft));
+                __hrtimer_start_range_ns(&rt_b->rt_period_timer, soft, delta,
+                                HRTIMER_MODE_ABS, 0);
         }
         spin_unlock(&rt_b->rt_runtime_lock);
 }
@@ -1146,7 +1153,8 @@ static __init void init_hrtick(void)
  */
 static void hrtick_start(struct rq *rq, u64 delay)
 {
-        hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay), HRTIMER_MODE_REL);
+        __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0,
+                        HRTIMER_MODE_REL, 0);
 }
 
 static inline void init_hrtick(void)
diff --git a/kernel/softirq.c b/kernel/softirq.c
index d105a82543d0..2fecefacdc5b 100644
--- a/kernel/softirq.c
+++ b/kernel/softirq.c
@@ -65,7 +65,7 @@ char *softirq_to_name[NR_SOFTIRQS] = {
  * to the pending events, so lets the scheduler to balance
  * the softirq load for us.
  */
-static inline void wakeup_softirqd(void)
+void wakeup_softirqd(void)
 {
         /* Interrupts are disabled: no need to stop preemption */
         struct task_struct *tsk = __get_cpu_var(ksoftirqd);