C++ rcu_bh_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)
{
  mutant_covered = 1;
 /* MUTANT (del_stmt) */ /* 	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.
 */
void rcu_check_callbacks(int cpu, int user)
{
	if (user ||
	    (idle_cpu(cpu) &&
	     !in_softirq() &&
	     hardirq_count() <= (1 << HARDIRQ_SHIFT)))
		rcu_sched_qs(cpu);
	else if (!in_softirq())
		rcu_bh_qs(cpu);
	rcu_preempt_check_callbacks();
}

/*
 * 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);
	}
}

asmlinkage void __do_softirq(void)
{
	struct softirq_action *h;
	__u32 pending;
	unsigned long end = jiffies + MAX_SOFTIRQ_TIME;
	int cpu;
	unsigned long old_flags = current->flags;
	int max_restart = MAX_SOFTIRQ_RESTART;

	/*
	 * Mask out PF_MEMALLOC s current task context is borrowed for the
	 * softirq. A softirq handled such as network RX might set PF_MEMALLOC
	 * again if the socket is related to swap
	 */
	current->flags &= ~PF_MEMALLOC;

	pending = local_softirq_pending();
	account_system_vtime(current);

	__local_bh_disable((unsigned long)__builtin_return_address(0),
				SOFTIRQ_OFFSET);
	lockdep_softirq_enter();

	cpu = smp_processor_id();
restart:
	/* Reset the pending bitmask before enabling irqs */
	set_softirq_pending(0);

	local_irq_enable();

	h = softirq_vec;

	do {
		if (pending & 1) {
			unsigned int vec_nr = h - softirq_vec;
			int prev_count = preempt_count();

			kstat_incr_softirqs_this_cpu(vec_nr);

			trace_softirq_entry(vec_nr);
			h->action(h);
			trace_softirq_exit(vec_nr);
			if (unlikely(prev_count != preempt_count())) {
				printk(KERN_ERR "huh, entered softirq %u %s %p"
				       "with preempt_count %08x,"
				       " exited with %08x?\n", vec_nr,
				       softirq_to_name[vec_nr], h->action,
				       prev_count, preempt_count());
				preempt_count_set(prev_count);
			}

			rcu_bh_qs(cpu);
		}
		h++;
		pending >>= 1;
	} while (pending);

	local_irq_disable();

	pending = local_softirq_pending();
	if (pending) {
		if (time_before(jiffies, end) && !need_resched() &&
		    --max_restart)
			goto restart;

		wakeup_softirqd();
	}

	lockdep_softirq_exit();

	account_system_vtime(current);
	__local_bh_enable(SOFTIRQ_OFFSET);
	tsk_restore_flags(current, old_flags, PF_MEMALLOC);
}

asmlinkage void __do_softirq(void)
{
	struct softirq_action *h;
	__u32 pending;
	unsigned long end = jiffies + MAX_SOFTIRQ_TIME;
	int cpu;

	pending = local_softirq_pending();
	account_system_vtime(current);

	__local_bh_disable((unsigned long)__builtin_return_address(0),
				SOFTIRQ_OFFSET);
	lockdep_softirq_enter();

	cpu = smp_processor_id();
restart:
	/* Reset the pending bitmask before enabling irqs */
	set_softirq_pending(0);

	local_irq_enable();

	h = softirq_vec;

	do {
		if (pending & 1) {
			unsigned int vec_nr = h - softirq_vec;
			int prev_count = preempt_count();

			kstat_incr_softirqs_this_cpu(vec_nr);

			trace_softirq_entry(vec_nr);
			h->action(h);
			trace_softirq_exit(vec_nr);
			if (unlikely(prev_count != preempt_count())) {
				printk(KERN_ERR "huh, entered softirq %u %s %p"
				       "with preempt_count %08x,"
				       " exited with %08x?\n", vec_nr,
				       softirq_to_name[vec_nr], h->action,
				       prev_count, preempt_count());
				preempt_count_set(prev_count);
			}

			rcu_bh_qs(cpu);
		}
		h++;
		pending >>= 1;
	} while (pending);

	local_irq_disable();

	pending = local_softirq_pending();
	if (pending) {
		if (time_before(jiffies, end) && !need_resched())
			goto restart;

		wakeup_softirqd();
	}

	lockdep_softirq_exit();

	account_system_vtime(current);
	__local_bh_enable(SOFTIRQ_OFFSET);
}

asmlinkage void __do_softirq(void)
{
	unsigned long end = jiffies + MAX_SOFTIRQ_TIME;
	unsigned long old_flags = current->flags;
	int max_restart = MAX_SOFTIRQ_RESTART;
	struct softirq_action *h;
	bool in_hardirq;
	__u32 pending;
	int softirq_bit;
	int cpu;

	/*
	 * Mask out PF_MEMALLOC s current task context is borrowed for the
	 * softirq. A softirq handled such as network RX might set PF_MEMALLOC
	 * again if the socket is related to swap
	 */
	current->flags &= ~PF_MEMALLOC;

	pending = local_softirq_pending();
	account_irq_enter_time(current);

	__local_bh_disable_ip(_RET_IP_, SOFTIRQ_OFFSET);
	in_hardirq = lockdep_softirq_start();

	cpu = smp_processor_id();
restart:
	/* Reset the pending bitmask before enabling irqs */
	set_softirq_pending(0);

	local_irq_enable();

	h = softirq_vec;

	while ((softirq_bit = ffs(pending))) {
		unsigned int vec_nr;
		int prev_count;

		h += softirq_bit - 1;

		vec_nr = h - softirq_vec;
		prev_count = preempt_count();

		kstat_incr_softirqs_this_cpu(vec_nr);

		trace_softirq_entry(vec_nr);
		h->action(h);
		trace_softirq_exit(vec_nr);
		if (unlikely(prev_count != preempt_count())) {
			pr_err("huh, entered softirq %u %s %p with preempt_count %08x, exited with %08x?\n",
			       vec_nr, softirq_to_name[vec_nr], h->action,
			       prev_count, preempt_count());
			preempt_count_set(prev_count);
		}
		rcu_bh_qs(cpu);
		h++;
		pending >>= softirq_bit;
	}

	local_irq_disable();

	pending = local_softirq_pending();
	if (pending) {
		if (time_before(jiffies, end) && !need_resched() &&
		    --max_restart)
			goto restart;

		wakeup_softirqd();
	}

	lockdep_softirq_end(in_hardirq);
	account_irq_exit_time(current);
	__local_bh_enable(SOFTIRQ_OFFSET);
	WARN_ON_ONCE(in_interrupt());
	tsk_restore_flags(current, old_flags, PF_MEMALLOC);
}