Re: [PATCH] Fix locking in flush_backlog

[Eric Dumazet <eric.dumazet@gmail.com>]

Le mardi 23 mars 2010 à 08:56 -0700, Tom Herbert a écrit :

> Eric,
> 
> I'm not sure what you're asking.  Do you just want to add spinlocks in
> the flush_backlog function without changing the mechanism to call the
> function on each CPU, or keep flush_backlog but call it from
> netdev_run_todo for each queue?
> 

keep flush_backlog() so that its role is obvious and indentation level
not too big.

static void flush_backlog(int cpu)
{
	struct softnet_data *queue = &per_cpu(softnet_data, cpu);
	struct sk_buff *skb, *tmp;
	unsigned long flags;

	spin_lock_irqsave(&queue->input_pkt_queue.lock, flags);
	skb_queue_walk_safe(&queue->input_pkt_queue, skb, tmp)
		if (skb->dev == dev) {
			__skb_unlink(skb, &queue->input_pkt_queue);
			kfree_skb(skb);
		}
	spin_unlock_irqrestore(&queue->input_pkt_queue.lock, flags);
}

And call it from netdev_run_todo() :

for_each_online_cpu(i)
	flush_backlog(i);

This adds two lines to netdev_run_todo() only.

Thanks