10 files changed, 68 insertions, 36 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index d724e7757cd1..72348dc192c1 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5680,11 +5680,6 @@ static void swevent_hlist_put(struct perf_event *event)
 {
         int cpu;
 
-        if (event->cpu != -1) {
-                swevent_hlist_put_cpu(event, event->cpu);
-                return;
-        }
-
         for_each_possible_cpu(cpu)
                 swevent_hlist_put_cpu(event, cpu);
 }
@@ -5718,9 +5713,6 @@ static int swevent_hlist_get(struct perf_event *event)
         int err;
         int cpu, failed_cpu;
 
-        if (event->cpu != -1)
-                return swevent_hlist_get_cpu(event, event->cpu);
-
         get_online_cpus();
         for_each_possible_cpu(cpu) {
                 err = swevent_hlist_get_cpu(event, cpu);
diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c
index cb228bf21760..abcd6ca86cb7 100644
--- a/kernel/irq/pm.c
+++ b/kernel/irq/pm.c
@@ -50,7 +50,7 @@ static void resume_irqs(bool want_early)
                 bool is_early = desc->action &&
                         desc->action->flags & IRQF_EARLY_RESUME;
 
-                if (is_early != want_early)
+                if (!is_early && want_early)
                         continue;
 
                 raw_spin_lock_irqsave(&desc->lock, flags);
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 6abb03dff5c0..08a765232432 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -1632,7 +1632,7 @@ module_param(rcu_idle_gp_delay, int, 0644);
 static int rcu_idle_lazy_gp_delay = RCU_IDLE_LAZY_GP_DELAY;
 module_param(rcu_idle_lazy_gp_delay, int, 0644);
 
-extern int tick_nohz_enabled;
+extern int tick_nohz_active;
 
 /*
  * Try to advance callbacks for all flavors of RCU on the current CPU, but
@@ -1729,7 +1729,7 @@ static void rcu_prepare_for_idle(int cpu)
         int tne;
 
         /* Handle nohz enablement switches conservatively. */
-        tne = ACCESS_ONCE(tick_nohz_enabled);
+        tne = ACCESS_ONCE(tick_nohz_active);
         if (tne != rdtp->tick_nohz_enabled_snap) {
                 if (rcu_cpu_has_callbacks(cpu, NULL))
                         invoke_rcu_core(); /* force nohz to see update. */
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index c1808606ee5f..e85cda20ab2b 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2660,6 +2660,7 @@ asmlinkage void __sched notrace preempt_schedule(void)
         } while (need_resched());
 }
 EXPORT_SYMBOL(preempt_schedule);
+#endif /* CONFIG_PREEMPT */
 
 /*
  * this is the entry point to schedule() from kernel preemption
@@ -2693,8 +2694,6 @@ asmlinkage void __sched preempt_schedule_irq(void)
         exception_exit(prev_state);
 }
 
-#endif /* CONFIG_PREEMPT */
-
 int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags,
                           void *key)
 {
@@ -4762,7 +4761,7 @@ static void rq_attach_root(struct rq *rq, struct root_domain *rd)
                 cpumask_clear_cpu(rq->cpu, old_rd->span);
 
                 /*
-                 * If we dont want to free the old_rt yet then
+                 * If we dont want to free the old_rd yet then
                  * set old_rd to NULL to skip the freeing later
                  * in this function:
                  */
@@ -4910,8 +4909,9 @@ static void update_top_cache_domain(int cpu)
         if (sd) {
                 id = cpumask_first(sched_domain_span(sd));
                 size = cpumask_weight(sched_domain_span(sd));
-                rcu_assign_pointer(per_cpu(sd_busy, cpu), sd->parent);
+                sd = sd->parent; /* sd_busy */
         }
+        rcu_assign_pointer(per_cpu(sd_busy, cpu), sd);
 
         rcu_assign_pointer(per_cpu(sd_llc, cpu), sd);
         per_cpu(sd_llc_size, cpu) = size;
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index e8b652ebe027..fd773ade1a31 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -5379,10 +5379,31 @@ void update_group_power(struct sched_domain *sd, int cpu)
                  */
 
                 for_each_cpu(cpu, sched_group_cpus(sdg)) {
-                        struct sched_group *sg = cpu_rq(cpu)->sd->groups;
+                        struct sched_group_power *sgp;
+                        struct rq *rq = cpu_rq(cpu);
 
-                        power_orig += sg->sgp->power_orig;
-                        power += sg->sgp->power;
+                        /*
+                         * build_sched_domains() -> init_sched_groups_power()
+                         * gets here before we've attached the domains to the
+                         * runqueues.
+                         *
+                         * Use power_of(), which is set irrespective of domains
+                         * in update_cpu_power().
+                         *
+                         * This avoids power/power_orig from being 0 and
+                         * causing divide-by-zero issues on boot.
+                         *
+                         * Runtime updates will correct power_orig.
+                         */
+                        if (unlikely(!rq->sd)) {
+                                power_orig += power_of(cpu);
+                                power += power_of(cpu);
+                                continue;
+                        }
+
+                        sgp = rq->sd->groups->sgp;
+                        power_orig += sgp->power_orig;
+                        power += sgp->power;
                 }
         } else  {
                 /*
diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c
index 64522ecdfe0e..162b03ab0ad2 100644
--- a/kernel/time/tick-common.c
+++ b/kernel/time/tick-common.c
@@ -33,6 +33,21 @@ DEFINE_PER_CPU(struct tick_device, tick_cpu_device);
  */
 ktime_t tick_next_period;
 ktime_t tick_period;
+
+/*
+ * tick_do_timer_cpu is a timer core internal variable which holds the CPU NR
+ * which is responsible for calling do_timer(), i.e. the timekeeping stuff. This
+ * variable has two functions:
+ *
+ * 1) Prevent a thundering herd issue of a gazillion of CPUs trying to grab the
+ *    timekeeping lock all at once. Only the CPU which is assigned to do the
+ *    update is handling it.
+ *
+ * 2) Hand off the duty in the NOHZ idle case by setting the value to
+ *    TICK_DO_TIMER_NONE, i.e. a non existing CPU. So the next cpu which looks
+ *    at it will take over and keep the time keeping alive.  The handover
+ *    procedure also covers cpu hotplug.
+ */
 int tick_do_timer_cpu __read_mostly = TICK_DO_TIMER_BOOT;
 
 /*
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 3612fc77f834..ea20f7d1ac2c 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -361,8 +361,8 @@ void __init tick_nohz_init(void)
 /*
  * NO HZ enabled ?
  */
-int tick_nohz_enabled __read_mostly  = 1;
-
+static int tick_nohz_enabled __read_mostly  = 1;
+int tick_nohz_active  __read_mostly;
 /*
  * Enable / Disable tickless mode
  */
@@ -465,7 +465,7 @@ u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time)
         struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
         ktime_t now, idle;
 
-        if (!tick_nohz_enabled)
+        if (!tick_nohz_active)
                 return -1;
 
         now = ktime_get();
@@ -506,7 +506,7 @@ u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time)
         struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
         ktime_t now, iowait;
 
-        if (!tick_nohz_enabled)
+        if (!tick_nohz_active)
                 return -1;
 
         now = ktime_get();
@@ -711,8 +711,10 @@ static bool can_stop_idle_tick(int cpu, struct tick_sched *ts)
                 return false;
         }
 
-        if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE))
+        if (unlikely(ts->nohz_mode == NOHZ_MODE_INACTIVE)) {
+                ts->sleep_length = (ktime_t) { .tv64 = NSEC_PER_SEC/HZ };
                 return false;
+        }
 
         if (need_resched())
                 return false;
@@ -799,11 +801,6 @@ void tick_nohz_idle_enter(void)
         local_irq_disable();
 
         ts = &__get_cpu_var(tick_cpu_sched);
-        /*
-         * set ts->inidle unconditionally. even if the system did not
-         * switch to nohz mode the cpu frequency governers rely on the
-         * update of the idle time accounting in tick_nohz_start_idle().
-         */
         ts->inidle = 1;
         __tick_nohz_idle_enter(ts);
 
@@ -973,7 +970,7 @@ static void tick_nohz_switch_to_nohz(void)
         struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
         ktime_t next;
 
-        if (!tick_nohz_enabled)
+        if (!tick_nohz_active)
                 return;
 
         local_irq_disable();
@@ -981,7 +978,7 @@ static void tick_nohz_switch_to_nohz(void)
                 local_irq_enable();
                 return;
         }
-
+        tick_nohz_active = 1;
         ts->nohz_mode = NOHZ_MODE_LOWRES;
 
         /*
@@ -1139,8 +1136,10 @@ void tick_setup_sched_timer(void)
         }
 
 #ifdef CONFIG_NO_HZ_COMMON
-        if (tick_nohz_enabled)
+        if (tick_nohz_enabled) {
                 ts->nohz_mode = NOHZ_MODE_HIGHRES;
+                tick_nohz_active = 1;
+        }
 #endif
 }
 #endif /* HIGH_RES_TIMERS */
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 3abf53418b67..87b4f00284c9 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1347,7 +1347,7 @@ static inline void old_vsyscall_fixup(struct timekeeper *tk)
         tk->xtime_nsec -= remainder;
         tk->xtime_nsec += 1ULL << tk->shift;
         tk->ntp_error += remainder << tk->ntp_error_shift;
-
+        tk->ntp_error -= (1ULL << tk->shift) << tk->ntp_error_shift;
 }
 #else
 #define old_vsyscall_fixup(tk)
diff --git a/kernel/timer.c b/kernel/timer.c
index 6582b82fa966..accfd241b9e5 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1518,9 +1518,8 @@ static int init_timers_cpu(int cpu)
                         /*
                          * The APs use this path later in boot
                          */
-                        base = kmalloc_node(sizeof(*base),
-                                                GFP_KERNEL | __GFP_ZERO,
-                                                cpu_to_node(cpu));
+                        base = kzalloc_node(sizeof(*base), GFP_KERNEL,
+                                            cpu_to_node(cpu));
                         if (!base)
                                 return -ENOMEM;
 
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 78e27e3b52ac..e854f420e033 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -24,6 +24,12 @@ static int	total_ref_count;
 static int perf_trace_event_perm(struct ftrace_event_call *tp_event,
                                  struct perf_event *p_event)
 {
+        if (tp_event->perf_perm) {
+                int ret = tp_event->perf_perm(tp_event, p_event);
+                if (ret)
+                        return ret;
+        }
+
         /* The ftrace function trace is allowed only for root. */
         if (ftrace_event_is_function(tp_event) &&
             perf_paranoid_tracepoint_raw() && !capable(CAP_SYS_ADMIN))
@@ -173,7 +179,7 @@ static int perf_trace_event_init(struct ftrace_event_call *tp_event,
 int perf_trace_init(struct perf_event *p_event)
 {
         struct ftrace_event_call *tp_event;
-        int event_id = p_event->attr.config;
+        u64 event_id = p_event->attr.config;
         int ret = -EINVAL;
 
         mutex_lock(&event_mutex);