*/
if (rdp->dynticks_nmi_nesting != 1) {
trace_rcu_dyntick(TPS("--="), rdp->dynticks_nmi_nesting, rdp->dynticks_nmi_nesting - 2, rdp->dynticks);
+ if (tick_nohz_full_cpu(rdp->cpu) &&
+ rdp->dynticks_nmi_nesting == 2 &&
+ rdp->rcu_urgent_qs && !rdp->rcu_forced_tick) {
+ rdp->rcu_forced_tick = true;
+ tick_dep_set_cpu(rdp->cpu, TICK_DEP_MASK_RCU);
+ }
WRITE_ONCE(rdp->dynticks_nmi_nesting, /* No store tearing. */
rdp->dynticks_nmi_nesting - 2);
return;
local_irq_restore(flags);
}
+/*
+ * If the scheduler-clock interrupt was enabled on a nohz_full CPU
+ * in order to get to a quiescent state, disable it.
+ */
+void rcu_disable_tick_upon_qs(struct rcu_data *rdp)
+{
+ if (tick_nohz_full_cpu(rdp->cpu) && rdp->rcu_forced_tick) {
+ tick_dep_clear_cpu(rdp->cpu, TICK_DEP_BIT_RCU);
+ rdp->rcu_forced_tick = false;
+ }
+}
+
/**
* rcu_is_watching - see if RCU thinks that the current CPU is not idle
*
if (!offloaded)
needwake = rcu_accelerate_cbs(rnp, rdp);
+ rcu_disable_tick_upon_qs(rdp);
rcu_report_qs_rnp(mask, rnp, rnp->gp_seq, flags);
/* ^^^ Released rnp->lock */
if (needwake)
int cpu;
unsigned long flags;
unsigned long mask;
+ struct rcu_data *rdp;
struct rcu_node *rnp;
rcu_for_each_leaf_node(rnp) {
for_each_leaf_node_possible_cpu(rnp, cpu) {
unsigned long bit = leaf_node_cpu_bit(rnp, cpu);
if ((rnp->qsmask & bit) != 0) {
- if (f(per_cpu_ptr(&rcu_data, cpu)))
+ rdp = per_cpu_ptr(&rcu_data, cpu);
+ if (f(rdp)) {
mask |= bit;
+ rcu_disable_tick_upon_qs(rdp);
+ }
}
}
if (mask != 0) {
rnp = __this_cpu_read(rcu_data.mynode);
for (; rnp != NULL; rnp = rnp->parent) {
ret = (READ_ONCE(rcu_state.gp_flags) & RCU_GP_FLAG_FQS) ||
- !raw_spin_trylock(&rnp->fqslock);
+ !raw_spin_trylock(&rnp->fqslock);
if (rnp_old != NULL)
raw_spin_unlock(&rnp_old->fqslock);
if (ret)
{
if (atomic_dec_and_test(&rcu_state.barrier_cpu_count)) {
rcu_barrier_trace(TPS("LastCB"), -1,
- rcu_state.barrier_sequence);
+ rcu_state.barrier_sequence);
complete(&rcu_state.barrier_completion);
} else {
rcu_barrier_trace(TPS("CB"), -1, rcu_state.barrier_sequence);
} else {
debug_rcu_head_unqueue(&rdp->barrier_head);
rcu_barrier_trace(TPS("IRQNQ"), -1,
- rcu_state.barrier_sequence);
+ rcu_state.barrier_sequence);
}
rcu_nocb_unlock(rdp);
}
/* Did someone else do our work for us? */
if (rcu_seq_done(&rcu_state.barrier_sequence, s)) {
rcu_barrier_trace(TPS("EarlyExit"), -1,
- rcu_state.barrier_sequence);
+ rcu_state.barrier_sequence);
smp_mb(); /* caller's subsequent code after above check. */
mutex_unlock(&rcu_state.barrier_mutex);
return;
continue;
if (rcu_segcblist_n_cbs(&rdp->cblist)) {
rcu_barrier_trace(TPS("OnlineQ"), cpu,
- rcu_state.barrier_sequence);
+ rcu_state.barrier_sequence);
smp_call_function_single(cpu, rcu_barrier_func, NULL, 1);
} else {
rcu_barrier_trace(TPS("OnlineNQ"), cpu,
- rcu_state.barrier_sequence);
+ rcu_state.barrier_sequence);
}
}
put_online_cpus();
rdp->rcu_onl_gp_seq = READ_ONCE(rcu_state.gp_seq);
rdp->rcu_onl_gp_flags = READ_ONCE(rcu_state.gp_flags);
if (rnp->qsmask & mask) { /* RCU waiting on incoming CPU? */
+ rcu_disable_tick_upon_qs(rdp);
/* Report QS -after- changing ->qsmaskinitnext! */
rcu_report_qs_rnp(mask, rnp, rnp->gp_seq, flags);
} else {