C++ rcu_sched_qs函数代码示例

/*
 * Check to see if the scheduling-clock interrupt came from an extended
 * quiescent state, and, if so, tell RCU about it.  This function must
 * be called from hardirq context.  It is normally called from the
 * scheduling-clock interrupt.
 */
void rcu_check_callbacks(int user)
{
	RCU_TRACE(check_cpu_stalls());
	if (user || rcu_is_cpu_rrupt_from_idle()) {
		rcu_sched_qs();
	}
	else if (!in_softirq()) {
		rcu_bh_qs();
	}
	if (user) {
		rcu_note_voluntary_context_switch(current);
	}
}

/*
 * Check to see if the scheduling-clock interrupt came from an extended
 * quiescent state, and, if so, tell RCU about it.  This function must
 * be called from hardirq context.  It is normally called from the
 * scheduling-clock interrupt.
 */
void rcu_check_callbacks(int user)
{
	RCU_TRACE(check_cpu_stalls());
 mutant_covered = 1;
 /* MUTANT (negate) */	if(! (user || rcu_is_cpu_rrupt_from_idle())) {
		rcu_sched_qs();
	}
	else if (!in_softirq()) {
		rcu_bh_qs();
	}
	if (user) {
		rcu_note_voluntary_context_switch(current);
	}
}

/*
 * Check to see if the scheduling-clock interrupt came from an extended
 * quiescent state, and, if so, tell RCU about it.  This function must
 * be called from hardirq context.  It is normally called from the
 * scheduling-clock interrupt.
 */
void rcu_check_callbacks(int user)
{
	RCU_TRACE(check_cpu_stalls());
	if (user || rcu_is_cpu_rrupt_from_idle()) {
		if (!__covered11) {__covered11 = 1; total_covered += 1;}
		rcu_sched_qs();
	}
	else if (!in_softirq()) {
		if (!__covered12) {__covered12 = 1; total_covered += 1;}
		rcu_bh_qs();
	}
	if (user) {
		if (!__covered13) {__covered13 = 1; total_covered += 1;}
		rcu_note_voluntary_context_switch(current);
	}
}

/* Common code for rcu_idle_enter() and rcu_irq_exit(), see kernel/rcutree.c. */
static void rcu_idle_enter_common(long long oldval)
{
	if (rcu_dynticks_nesting) {
		RCU_TRACE(trace_rcu_dyntick("--=",
					    oldval, rcu_dynticks_nesting));
		return;
	}
	RCU_TRACE(trace_rcu_dyntick("Start", oldval, rcu_dynticks_nesting));
	if (!is_idle_task(current)) {
		struct task_struct *idle = idle_task(smp_processor_id());

		RCU_TRACE(trace_rcu_dyntick("Error on entry: not idle task",
					    oldval, rcu_dynticks_nesting));
		ftrace_dump(DUMP_ALL);
		WARN_ONCE(1, "Current pid: %d comm: %s / Idle pid: %d comm: %s",
			  current->pid, current->comm,
			  idle->pid, idle->comm); /* must be idle task! */
	}
	rcu_sched_qs(0); /* implies rcu_bh_qsctr_inc(0) */
}

/* Common code for rcu_idle_enter() and rcu_irq_exit(), see kernel/rcu/tree.c. */
static void rcu_idle_enter_common(long long newval)
{
	if (newval) {
		RCU_TRACE(trace_rcu_dyntick(TPS("--="),
					    rcu_dynticks_nesting, newval));
		rcu_dynticks_nesting = newval;
		return;
	}
	RCU_TRACE(trace_rcu_dyntick(TPS("Start"),
				    rcu_dynticks_nesting, newval));
	if (IS_ENABLED(CONFIG_RCU_TRACE) && !is_idle_task(current)) {
		struct task_struct *idle __maybe_unused = idle_task(smp_processor_id());

		RCU_TRACE(trace_rcu_dyntick(TPS("Entry error: not idle task"),
					    rcu_dynticks_nesting, newval));
		ftrace_dump(DUMP_ALL);
		WARN_ONCE(1, "Current pid: %d comm: %s / Idle pid: %d comm: %s",
			  current->pid, current->comm,
			  idle->pid, idle->comm); /* must be idle task! */
	}
	rcu_sched_qs(); /* implies rcu_bh_inc() */
	barrier();
	rcu_dynticks_nesting = newval;
}

/*
 * Enter dynticks-idle mode, which is an extended quiescent state
 * if we have fully entered that mode (i.e., if the new value of
 * dynticks_nesting is zero).
 */
void rcu_enter_nohz(void)
{
	if (--rcu_dynticks_nesting == 0)
		rcu_sched_qs(0); /* implies rcu_bh_qsctr_inc(0) */
}

void rcu_note_context_switch(int cpu)
{
	rcu_sched_qs(cpu);
	rcu_preempt_note_context_switch(cpu);
}