示例#1
0
static inline bool lockdep_softirq_start(void)
{
	bool in_hardirq = false;

	if (trace_hardirq_context(current)) {
		in_hardirq = true;
		trace_hardirq_exit();
	}

	lockdep_softirq_enter();

	return in_hardirq;
}
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);
}