10 files changed, 133 insertions, 53 deletions

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index f2da20fda02d..3efdf2870a35 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1154,7 +1154,7 @@ static int x86_pmu_handle_irq(struct pt_regs *regs)
                 /*
                  * event overflow
                  */
-                handled         = 1;
+                handled++;
                 data.period     = event->hw.last_period;
 
                 if (!x86_perf_event_set_period(event))
@@ -1200,12 +1200,20 @@ void perf_events_lapic_init(void)
         apic_write(APIC_LVTPC, APIC_DM_NMI);
 }
 
+struct pmu_nmi_state {
+        unsigned int    marked;
+        int             handled;
+};
+
+static DEFINE_PER_CPU(struct pmu_nmi_state, pmu_nmi);
+
 static int __kprobes
 perf_event_nmi_handler(struct notifier_block *self,
                          unsigned long cmd, void *__args)
 {
         struct die_args *args = __args;
-        struct pt_regs *regs;
+        unsigned int this_nmi;
+        int handled;
 
         if (!atomic_read(&active_events))
                 return NOTIFY_DONE;
@@ -1214,22 +1222,47 @@ perf_event_nmi_handler(struct notifier_block *self,
         case DIE_NMI:
         case DIE_NMI_IPI:
                 break;
-
+        case DIE_NMIUNKNOWN:
+                this_nmi = percpu_read(irq_stat.__nmi_count);
+                if (this_nmi != __get_cpu_var(pmu_nmi).marked)
+                        /* let the kernel handle the unknown nmi */
+                        return NOTIFY_DONE;
+                /*
+                 * This one is a PMU back-to-back nmi. Two events
+                 * trigger 'simultaneously' raising two back-to-back
+                 * NMIs. If the first NMI handles both, the latter
+                 * will be empty and daze the CPU. So, we drop it to
+                 * avoid false-positive 'unknown nmi' messages.
+                 */
+                return NOTIFY_STOP;
         default:
                 return NOTIFY_DONE;
         }
 
-        regs = args->regs;
-
         apic_write(APIC_LVTPC, APIC_DM_NMI);
-        /*
-         * Can't rely on the handled return value to say it was our NMI, two
-         * events could trigger 'simultaneously' raising two back-to-back NMIs.
-         *
-         * If the first NMI handles both, the latter will be empty and daze
-         * the CPU.
-         */
-        x86_pmu.handle_irq(regs);
+
+        handled = x86_pmu.handle_irq(args->regs);
+        if (!handled)
+                return NOTIFY_DONE;
+
+        this_nmi = percpu_read(irq_stat.__nmi_count);
+        if ((handled > 1) ||
+                /* the next nmi could be a back-to-back nmi */
+            ((__get_cpu_var(pmu_nmi).marked == this_nmi) &&
+             (__get_cpu_var(pmu_nmi).handled > 1))) {
+                /*
+                 * We could have two subsequent back-to-back nmis: The
+                 * first handles more than one counter, the 2nd
+                 * handles only one counter and the 3rd handles no
+                 * counter.
+                 *
+                 * This is the 2nd nmi because the previous was
+                 * handling more than one counter. We will mark the
+                 * next (3rd) and then drop it if unhandled.
+                 */
+                __get_cpu_var(pmu_nmi).marked   = this_nmi + 1;
+                __get_cpu_var(pmu_nmi).handled  = handled;
+        }
 
         return NOTIFY_STOP;
 }
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index d8d86d014008..ee05c90012d2 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -712,7 +712,8 @@ static int intel_pmu_handle_irq(struct pt_regs *regs)
         struct perf_sample_data data;
         struct cpu_hw_events *cpuc;
         int bit, loops;
-        u64 ack, status;
+        u64 status;
+        int handled = 0;
 
         perf_sample_data_init(&data, 0);
 
@@ -728,6 +729,7 @@ static int intel_pmu_handle_irq(struct pt_regs *regs)
 
         loops = 0;
 again:
+        intel_pmu_ack_status(status);
         if (++loops > 100) {
                 WARN_ONCE(1, "perfevents: irq loop stuck!\n");
                 perf_event_print_debug();
@@ -736,19 +738,22 @@ again:
         }
 
         inc_irq_stat(apic_perf_irqs);
-        ack = status;
 
         intel_pmu_lbr_read();
 
         /*
          * PEBS overflow sets bit 62 in the global status register
          */
-        if (__test_and_clear_bit(62, (unsigned long *)&status))
+        if (__test_and_clear_bit(62, (unsigned long *)&status)) {
+                handled++;
                 x86_pmu.drain_pebs(regs);
+        }
 
         for_each_set_bit(bit, (unsigned long *)&status, X86_PMC_IDX_MAX) {
                 struct perf_event *event = cpuc->events[bit];
 
+                handled++;
+
                 if (!test_bit(bit, cpuc->active_mask))
                         continue;
 
@@ -761,8 +766,6 @@ again:
                         x86_pmu_stop(event);
         }
 
-        intel_pmu_ack_status(ack);
-
         /*
          * Repeat if there is more work to be done:
          */
@@ -772,7 +775,7 @@ again:
 
 done:
         intel_pmu_enable_all(0);
-        return 1;
+        return handled;
 }
 
 static struct event_constraint *
diff --git a/arch/x86/kernel/cpu/perf_event_p4.c b/arch/x86/kernel/cpu/perf_event_p4.c
index 7e578e9cc58b..b560db3305be 100644
--- a/arch/x86/kernel/cpu/perf_event_p4.c
+++ b/arch/x86/kernel/cpu/perf_event_p4.c
@@ -692,7 +692,7 @@ static int p4_pmu_handle_irq(struct pt_regs *regs)
                 inc_irq_stat(apic_perf_irqs);
         }
 
-        return handled > 0;
+        return handled;
 }
 
 /*
diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index f6b48f6c5951..cfe4faabb0f6 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -568,8 +568,13 @@ static int __init init_sysfs(void)
         int error;
 
         error = sysdev_class_register(&oprofile_sysclass);
-        if (!error)
-                error = sysdev_register(&device_oprofile);
+        if (error)
+                return error;
+
+        error = sysdev_register(&device_oprofile);
+        if (error)
+                sysdev_class_unregister(&oprofile_sysclass);
+
         return error;
 }
 
@@ -580,8 +585,10 @@ static void exit_sysfs(void)
 }
 
 #else
-#define init_sysfs() do { } while (0)
-#define exit_sysfs() do { } while (0)
+
+static inline int  init_sysfs(void) { return 0; }
+static inline void exit_sysfs(void) { }
+
 #endif /* CONFIG_PM */
 
 static int __init p4_init(char **cpu_type)
@@ -695,6 +702,8 @@ int __init op_nmi_init(struct oprofile_operations *ops)
         char *cpu_type = NULL;
         int ret = 0;
 
+        using_nmi = 0;
+
         if (!cpu_has_apic)
                 return -ENODEV;
 
@@ -774,7 +783,10 @@ int __init op_nmi_init(struct oprofile_operations *ops)
 
         mux_init(ops);
 
-        init_sysfs();
+        ret = init_sysfs();
+        if (ret)
+                return ret;
+
         using_nmi = 1;
         printk(KERN_INFO "oprofile: using NMI interrupt.\n");
         return 0;
diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c
index a9352b2c7ac4..b7e755f4178a 100644
--- a/drivers/oprofile/buffer_sync.c
+++ b/drivers/oprofile/buffer_sync.c
@@ -141,16 +141,6 @@ static struct notifier_block module_load_nb = {
         .notifier_call = module_load_notify,
 };
 
-
-static void end_sync(void)
-{
-        end_cpu_work();
-        /* make sure we don't leak task structs */
-        process_task_mortuary();
-        process_task_mortuary();
-}
-
-
 int sync_start(void)
 {
         int err;
@@ -158,7 +148,7 @@ int sync_start(void)
         if (!zalloc_cpumask_var(&marked_cpus, GFP_KERNEL))
                 return -ENOMEM;
 
-        start_cpu_work();
+        mutex_lock(&buffer_mutex);
 
         err = task_handoff_register(&task_free_nb);
         if (err)
@@ -173,7 +163,10 @@ int sync_start(void)
         if (err)
                 goto out4;
 
+        start_cpu_work();
+
 out:
+        mutex_unlock(&buffer_mutex);
         return err;
 out4:
         profile_event_unregister(PROFILE_MUNMAP, &munmap_nb);
@@ -182,7 +175,6 @@ out3:
 out2:
         task_handoff_unregister(&task_free_nb);
 out1:
-        end_sync();
         free_cpumask_var(marked_cpus);
         goto out;
 }
@@ -190,11 +182,20 @@ out1:
 
 void sync_stop(void)
 {
+        /* flush buffers */
+        mutex_lock(&buffer_mutex);
+        end_cpu_work();
         unregister_module_notifier(&module_load_nb);
         profile_event_unregister(PROFILE_MUNMAP, &munmap_nb);
         profile_event_unregister(PROFILE_TASK_EXIT, &task_exit_nb);
         task_handoff_unregister(&task_free_nb);
-        end_sync();
+        mutex_unlock(&buffer_mutex);
+        flush_scheduled_work();
+
+        /* make sure we don't leak task structs */
+        process_task_mortuary();
+        process_task_mortuary();
+
         free_cpumask_var(marked_cpus);
 }
 
diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c
index 219f79e2210a..f179ac2ea801 100644
--- a/drivers/oprofile/cpu_buffer.c
+++ b/drivers/oprofile/cpu_buffer.c
@@ -120,8 +120,6 @@ void end_cpu_work(void)
 
                 cancel_delayed_work(&b->work);
         }
-
-        flush_scheduled_work();
 }
 
 /*
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 403d1804b198..657555a5f30f 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -402,11 +402,31 @@ static void perf_group_detach(struct perf_event *event)
         }
 }
 
+static inline int
+event_filter_match(struct perf_event *event)
+{
+        return event->cpu == -1 || event->cpu == smp_processor_id();
+}
+
 static void
 event_sched_out(struct perf_event *event,
                   struct perf_cpu_context *cpuctx,
                   struct perf_event_context *ctx)
 {
+        u64 delta;
+        /*
+         * An event which could not be activated because of
+         * filter mismatch still needs to have its timings
+         * maintained, otherwise bogus information is return
+         * via read() for time_enabled, time_running:
+         */
+        if (event->state == PERF_EVENT_STATE_INACTIVE
+            && !event_filter_match(event)) {
+                delta = ctx->time - event->tstamp_stopped;
+                event->tstamp_running += delta;
+                event->tstamp_stopped = ctx->time;
+        }
+
         if (event->state != PERF_EVENT_STATE_ACTIVE)
                 return;
 
@@ -432,9 +452,7 @@ group_sched_out(struct perf_event *group_event,
                 struct perf_event_context *ctx)
 {
         struct perf_event *event;
-
-        if (group_event->state != PERF_EVENT_STATE_ACTIVE)
-                return;
+        int state = group_event->state;
 
         event_sched_out(group_event, cpuctx, ctx);
 
@@ -444,7 +462,7 @@ group_sched_out(struct perf_event *group_event,
         list_for_each_entry(event, &group_event->sibling_list, group_entry)
                 event_sched_out(event, cpuctx, ctx);
 
-        if (group_event->attr.exclusive)
+        if (state == PERF_EVENT_STATE_ACTIVE && group_event->attr.exclusive)
                 cpuctx->exclusive = 0;
 }
 
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 0d88ce9b9fb8..7cb1f45a1de1 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -381,12 +381,19 @@ static int function_stat_show(struct seq_file *m, void *v)
 {
         struct ftrace_profile *rec = v;
         char str[KSYM_SYMBOL_LEN];
+        int ret = 0;
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
-        static DEFINE_MUTEX(mutex);
         static struct trace_seq s;
         unsigned long long avg;
         unsigned long long stddev;
 #endif
+        mutex_lock(&ftrace_profile_lock);
+
+        /* we raced with function_profile_reset() */
+        if (unlikely(rec->counter == 0)) {
+                ret = -EBUSY;
+                goto out;
+        }
 
         kallsyms_lookup(rec->ip, NULL, NULL, NULL, str);
         seq_printf(m, "  %-30.30s  %10lu", str, rec->counter);
@@ -408,7 +415,6 @@ static int function_stat_show(struct seq_file *m, void *v)
                 do_div(stddev, (rec->counter - 1) * 1000);
         }
 
-        mutex_lock(&mutex);
         trace_seq_init(&s);
         trace_print_graph_duration(rec->time, &s);
         trace_seq_puts(&s, "    ");
@@ -416,11 +422,12 @@ static int function_stat_show(struct seq_file *m, void *v)
         trace_seq_puts(&s, "    ");
         trace_print_graph_duration(stddev, &s);
         trace_print_seq(m, &s);
-        mutex_unlock(&mutex);
 #endif
         seq_putc(m, '\n');
+out:
+        mutex_unlock(&ftrace_profile_lock);
 
-        return 0;
+        return ret;
 }
 
 static void ftrace_profile_reset(struct ftrace_profile_stat *stat)
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 0d53c8e853b1..7f9c3c52ecc1 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -122,7 +122,7 @@ static void __touch_watchdog(void)
 
 void touch_softlockup_watchdog(void)
 {
-        __get_cpu_var(watchdog_touch_ts) = 0;
+        __raw_get_cpu_var(watchdog_touch_ts) = 0;
 }
 EXPORT_SYMBOL(touch_softlockup_watchdog);
 
@@ -142,7 +142,14 @@ void touch_all_softlockup_watchdogs(void)
 #ifdef CONFIG_HARDLOCKUP_DETECTOR
 void touch_nmi_watchdog(void)
 {
-        __get_cpu_var(watchdog_nmi_touch) = true;
+        if (watchdog_enabled) {
+                unsigned cpu;
+
+                for_each_present_cpu(cpu) {
+                        if (per_cpu(watchdog_nmi_touch, cpu) != true)
+                                per_cpu(watchdog_nmi_touch, cpu) = true;
+                }
+        }
         touch_softlockup_watchdog();
 }
 EXPORT_SYMBOL(touch_nmi_watchdog);
@@ -433,6 +440,9 @@ static int watchdog_enable(int cpu)
                 wake_up_process(p);
         }
 
+        /* if any cpu succeeds, watchdog is considered enabled for the system */
+        watchdog_enabled = 1;
+
         return 0;
 }
 
@@ -455,9 +465,6 @@ static void watchdog_disable(int cpu)
                 per_cpu(softlockup_watchdog, cpu) = NULL;
                 kthread_stop(p);
         }
-
-        /* if any cpu succeeds, watchdog is considered enabled for the system */
-        watchdog_enabled = 1;
 }
 
 static void watchdog_enable_all_cpus(void)
diff --git a/tools/perf/util/callchain.h b/tools/perf/util/callchain.h
index 624a96c636fd..6de4313924fb 100644
--- a/tools/perf/util/callchain.h
+++ b/tools/perf/util/callchain.h
@@ -50,6 +50,7 @@ static inline void callchain_init(struct callchain_node *node)
         INIT_LIST_HEAD(&node->children);
         INIT_LIST_HEAD(&node->val);
 
+        node->children_hit = 0;
         node->parent = NULL;
         node->hit = 0;
 }