summaryrefslogtreecommitdiff
path: root/kernel
diff options
context:
space:
mode:
Diffstat (limited to 'kernel')
-rw-r--r--kernel/events/core.c8
-rw-r--r--kernel/irq/pm.c2
-rw-r--r--kernel/rcu/tree_plugin.h4
-rw-r--r--kernel/sched/core.c8
-rw-r--r--kernel/sched/fair.c27
-rw-r--r--kernel/time/tick-common.c15
-rw-r--r--kernel/time/tick-sched.c25
-rw-r--r--kernel/time/timekeeping.c2
-rw-r--r--kernel/timer.c5
-rw-r--r--kernel/trace/trace_event_perf.c8
-rw-r--r--kernel/trace/trace_events.c3
-rw-r--r--kernel/trace/trace_syscalls.c10
12 files changed, 71 insertions, 46 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);
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index f919a2e21bf3..a11800ae96de 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -2314,6 +2314,9 @@ int event_trace_del_tracer(struct trace_array *tr)
/* Disable any running events */
__ftrace_set_clr_event_nolock(tr, NULL, NULL, NULL, 0);
+ /* Access to events are within rcu_read_lock_sched() */
+ synchronize_sched();
+
down_write(&trace_event_sem);
__trace_remove_event_dirs(tr);
debugfs_remove_recursive(tr->event_dir);
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index e4b6d11bdf78..ea90eb5f6f17 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -431,11 +431,6 @@ static void unreg_event_syscall_enter(struct ftrace_event_file *file,
if (!tr->sys_refcount_enter)
unregister_trace_sys_enter(ftrace_syscall_enter, tr);
mutex_unlock(&syscall_trace_lock);
- /*
- * Callers expect the event to be completely disabled on
- * return, so wait for current handlers to finish.
- */
- synchronize_sched();
}
static int reg_event_syscall_exit(struct ftrace_event_file *file,
@@ -474,11 +469,6 @@ static void unreg_event_syscall_exit(struct ftrace_event_file *file,
if (!tr->sys_refcount_exit)
unregister_trace_sys_exit(ftrace_syscall_exit, tr);
mutex_unlock(&syscall_trace_lock);
- /*
- * Callers expect the event to be completely disabled on
- * return, so wait for current handlers to finish.
- */
- synchronize_sched();
}
static int __init init_syscall_trace(struct ftrace_event_call *call)