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-rw-r--r--kernel/rcu/tree_plugin.h144
1 files changed, 41 insertions, 103 deletions
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 962d1d58992..cbc2c45265e 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -116,7 +116,7 @@ static void __init rcu_bootup_announce_oddness(void)
#ifdef CONFIG_TREE_PREEMPT_RCU
RCU_STATE_INITIALIZER(rcu_preempt, 'p', call_rcu);
-static struct rcu_state *rcu_state = &rcu_preempt_state;
+static struct rcu_state *rcu_state_p = &rcu_preempt_state;
static int rcu_preempted_readers_exp(struct rcu_node *rnp);
@@ -149,15 +149,6 @@ long rcu_batches_completed(void)
EXPORT_SYMBOL_GPL(rcu_batches_completed);
/*
- * Force a quiescent state for preemptible RCU.
- */
-void rcu_force_quiescent_state(void)
-{
- force_quiescent_state(&rcu_preempt_state);
-}
-EXPORT_SYMBOL_GPL(rcu_force_quiescent_state);
-
-/*
* Record a preemptible-RCU quiescent state for the specified CPU. Note
* that this just means that the task currently running on the CPU is
* not in a quiescent state. There might be any number of tasks blocked
@@ -688,20 +679,6 @@ void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
}
EXPORT_SYMBOL_GPL(call_rcu);
-/*
- * Queue an RCU callback for lazy invocation after a grace period.
- * This will likely be later named something like "call_rcu_lazy()",
- * but this change will require some way of tagging the lazy RCU
- * callbacks in the list of pending callbacks. Until then, this
- * function may only be called from __kfree_rcu().
- */
-void kfree_call_rcu(struct rcu_head *head,
- void (*func)(struct rcu_head *rcu))
-{
- __call_rcu(head, func, &rcu_preempt_state, -1, 1);
-}
-EXPORT_SYMBOL_GPL(kfree_call_rcu);
-
/**
* synchronize_rcu - wait until a grace period has elapsed.
*
@@ -970,7 +947,7 @@ void exit_rcu(void)
#else /* #ifdef CONFIG_TREE_PREEMPT_RCU */
-static struct rcu_state *rcu_state = &rcu_sched_state;
+static struct rcu_state *rcu_state_p = &rcu_sched_state;
/*
* Tell them what RCU they are running.
@@ -991,16 +968,6 @@ long rcu_batches_completed(void)
EXPORT_SYMBOL_GPL(rcu_batches_completed);
/*
- * Force a quiescent state for RCU, which, because there is no preemptible
- * RCU, becomes the same as rcu-sched.
- */
-void rcu_force_quiescent_state(void)
-{
- rcu_sched_force_quiescent_state();
-}
-EXPORT_SYMBOL_GPL(rcu_force_quiescent_state);
-
-/*
* Because preemptible RCU does not exist, we never have to check for
* CPUs being in quiescent states.
*/
@@ -1080,22 +1047,6 @@ static void rcu_preempt_check_callbacks(int cpu)
}
/*
- * Queue an RCU callback for lazy invocation after a grace period.
- * This will likely be later named something like "call_rcu_lazy()",
- * but this change will require some way of tagging the lazy RCU
- * callbacks in the list of pending callbacks. Until then, this
- * function may only be called from __kfree_rcu().
- *
- * Because there is no preemptible RCU, we use RCU-sched instead.
- */
-void kfree_call_rcu(struct rcu_head *head,
- void (*func)(struct rcu_head *rcu))
-{
- __call_rcu(head, func, &rcu_sched_state, -1, 1);
-}
-EXPORT_SYMBOL_GPL(kfree_call_rcu);
-
-/*
* Wait for an rcu-preempt grace period, but make it happen quickly.
* But because preemptible RCU does not exist, map to rcu-sched.
*/
@@ -1517,11 +1468,11 @@ static int __init rcu_spawn_kthreads(void)
for_each_possible_cpu(cpu)
per_cpu(rcu_cpu_has_work, cpu) = 0;
BUG_ON(smpboot_register_percpu_thread(&rcu_cpu_thread_spec));
- rnp = rcu_get_root(rcu_state);
- (void)rcu_spawn_one_boost_kthread(rcu_state, rnp);
+ rnp = rcu_get_root(rcu_state_p);
+ (void)rcu_spawn_one_boost_kthread(rcu_state_p, rnp);
if (NUM_RCU_NODES > 1) {
- rcu_for_each_leaf_node(rcu_state, rnp)
- (void)rcu_spawn_one_boost_kthread(rcu_state, rnp);
+ rcu_for_each_leaf_node(rcu_state_p, rnp)
+ (void)rcu_spawn_one_boost_kthread(rcu_state_p, rnp);
}
return 0;
}
@@ -1529,12 +1480,12 @@ early_initcall(rcu_spawn_kthreads);
static void rcu_prepare_kthreads(int cpu)
{
- struct rcu_data *rdp = per_cpu_ptr(rcu_state->rda, cpu);
+ struct rcu_data *rdp = per_cpu_ptr(rcu_state_p->rda, cpu);
struct rcu_node *rnp = rdp->mynode;
/* Fire up the incoming CPU's kthread and leaf rcu_node kthread. */
if (rcu_scheduler_fully_active)
- (void)rcu_spawn_one_boost_kthread(rcu_state, rnp);
+ (void)rcu_spawn_one_boost_kthread(rcu_state_p, rnp);
}
#else /* #ifdef CONFIG_RCU_BOOST */
@@ -1744,6 +1695,7 @@ int rcu_needs_cpu(int cpu, unsigned long *dj)
static void rcu_prepare_for_idle(int cpu)
{
#ifndef CONFIG_RCU_NOCB_CPU_ALL
+ bool needwake;
struct rcu_data *rdp;
struct rcu_dynticks *rdtp = &per_cpu(rcu_dynticks, cpu);
struct rcu_node *rnp;
@@ -1792,8 +1744,10 @@ static void rcu_prepare_for_idle(int cpu)
rnp = rdp->mynode;
raw_spin_lock(&rnp->lock); /* irqs already disabled. */
smp_mb__after_unlock_lock();
- rcu_accelerate_cbs(rsp, rnp, rdp);
+ needwake = rcu_accelerate_cbs(rsp, rnp, rdp);
raw_spin_unlock(&rnp->lock); /* irqs remain disabled. */
+ if (needwake)
+ rcu_gp_kthread_wake(rsp);
}
#endif /* #ifndef CONFIG_RCU_NOCB_CPU_ALL */
}
@@ -1855,7 +1809,7 @@ static void rcu_oom_notify_cpu(void *unused)
struct rcu_data *rdp;
for_each_rcu_flavor(rsp) {
- rdp = __this_cpu_ptr(rsp->rda);
+ rdp = raw_cpu_ptr(rsp->rda);
if (rdp->qlen_lazy != 0) {
atomic_inc(&oom_callback_count);
rsp->call(&rdp->oom_head, rcu_oom_callback);
@@ -1997,7 +1951,7 @@ static void increment_cpu_stall_ticks(void)
struct rcu_state *rsp;
for_each_rcu_flavor(rsp)
- __this_cpu_ptr(rsp->rda)->ticks_this_gp++;
+ raw_cpu_inc(rsp->rda->ticks_this_gp);
}
#else /* #ifdef CONFIG_RCU_CPU_STALL_INFO */
@@ -2068,19 +2022,6 @@ static int __init parse_rcu_nocb_poll(char *arg)
early_param("rcu_nocb_poll", parse_rcu_nocb_poll);
/*
- * Do any no-CBs CPUs need another grace period?
- *
- * Interrupts must be disabled. If the caller does not hold the root
- * rnp_node structure's ->lock, the results are advisory only.
- */
-static int rcu_nocb_needs_gp(struct rcu_state *rsp)
-{
- struct rcu_node *rnp = rcu_get_root(rsp);
-
- return rnp->need_future_gp[(ACCESS_ONCE(rnp->completed) + 1) & 0x1];
-}
-
-/*
* Wake up any no-CBs CPUs' kthreads that were waiting on the just-ended
* grace period.
*/
@@ -2109,7 +2050,7 @@ static void rcu_init_one_nocb(struct rcu_node *rnp)
}
#ifndef CONFIG_RCU_NOCB_CPU_ALL
-/* Is the specified CPU a no-CPUs CPU? */
+/* Is the specified CPU a no-CBs CPU? */
bool rcu_is_nocb_cpu(int cpu)
{
if (have_rcu_nocb_mask)
@@ -2243,12 +2184,15 @@ static void rcu_nocb_wait_gp(struct rcu_data *rdp)
unsigned long c;
bool d;
unsigned long flags;
+ bool needwake;
struct rcu_node *rnp = rdp->mynode;
raw_spin_lock_irqsave(&rnp->lock, flags);
smp_mb__after_unlock_lock();
- c = rcu_start_future_gp(rnp, rdp);
+ needwake = rcu_start_future_gp(rnp, rdp, &c);
raw_spin_unlock_irqrestore(&rnp->lock, flags);
+ if (needwake)
+ rcu_gp_kthread_wake(rdp->rsp);
/*
* Wait for the grace period. Do so interruptibly to avoid messing
@@ -2402,11 +2346,6 @@ static bool init_nocb_callback_list(struct rcu_data *rdp)
#else /* #ifdef CONFIG_RCU_NOCB_CPU */
-static int rcu_nocb_needs_gp(struct rcu_state *rsp)
-{
- return 0;
-}
-
static void rcu_nocb_gp_cleanup(struct rcu_state *rsp, struct rcu_node *rnp)
{
}
@@ -2523,9 +2462,9 @@ static void rcu_sysidle_enter(struct rcu_dynticks *rdtp, int irq)
/* Record start of fully idle period. */
j = jiffies;
ACCESS_ONCE(rdtp->dynticks_idle_jiffies) = j;
- smp_mb__before_atomic_inc();
+ smp_mb__before_atomic();
atomic_inc(&rdtp->dynticks_idle);
- smp_mb__after_atomic_inc();
+ smp_mb__after_atomic();
WARN_ON_ONCE(atomic_read(&rdtp->dynticks_idle) & 0x1);
}
@@ -2590,9 +2529,9 @@ static void rcu_sysidle_exit(struct rcu_dynticks *rdtp, int irq)
}
/* Record end of idle period. */
- smp_mb__before_atomic_inc();
+ smp_mb__before_atomic();
atomic_inc(&rdtp->dynticks_idle);
- smp_mb__after_atomic_inc();
+ smp_mb__after_atomic();
WARN_ON_ONCE(!(atomic_read(&rdtp->dynticks_idle) & 0x1));
/*
@@ -2657,20 +2596,6 @@ static bool is_sysidle_rcu_state(struct rcu_state *rsp)
}
/*
- * Bind the grace-period kthread for the sysidle flavor of RCU to the
- * timekeeping CPU.
- */
-static void rcu_bind_gp_kthread(void)
-{
- int cpu = ACCESS_ONCE(tick_do_timer_cpu);
-
- if (cpu < 0 || cpu >= nr_cpu_ids)
- return;
- if (raw_smp_processor_id() != cpu)
- set_cpus_allowed_ptr(current, cpumask_of(cpu));
-}
-
-/*
* Return a delay in jiffies based on the number of CPUs, rcu_node
* leaf fanout, and jiffies tick rate. The idea is to allow larger
* systems more time to transition to full-idle state in order to
@@ -2734,7 +2659,8 @@ static void rcu_sysidle(unsigned long j)
static void rcu_sysidle_cancel(void)
{
smp_mb();
- ACCESS_ONCE(full_sysidle_state) = RCU_SYSIDLE_NOT;
+ if (full_sysidle_state > RCU_SYSIDLE_SHORT)
+ ACCESS_ONCE(full_sysidle_state) = RCU_SYSIDLE_NOT;
}
/*
@@ -2880,10 +2806,6 @@ static bool is_sysidle_rcu_state(struct rcu_state *rsp)
return false;
}
-static void rcu_bind_gp_kthread(void)
-{
-}
-
static void rcu_sysidle_report_gp(struct rcu_state *rsp, int isidle,
unsigned long maxj)
{
@@ -2914,3 +2836,19 @@ static bool rcu_nohz_full_cpu(struct rcu_state *rsp)
#endif /* #ifdef CONFIG_NO_HZ_FULL */
return 0;
}
+
+/*
+ * Bind the grace-period kthread for the sysidle flavor of RCU to the
+ * timekeeping CPU.
+ */
+static void rcu_bind_gp_kthread(void)
+{
+#ifdef CONFIG_NO_HZ_FULL
+ int cpu = ACCESS_ONCE(tick_do_timer_cpu);
+
+ if (cpu < 0 || cpu >= nr_cpu_ids)
+ return;
+ if (raw_smp_processor_id() != cpu)
+ set_cpus_allowed_ptr(current, cpumask_of(cpu));
+#endif /* #ifdef CONFIG_NO_HZ_FULL */
+}