Re: [PATCH] drop_monitor: convert to modular building

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

On Wed, 2012-05-16 at 10:27 -0400, Neil Horman wrote:
> When I first wrote drop monitor I wrote it to just build monolithically.  There
> is no reason it can't be built modularly as well, so lets give it that
> flexibiity.

> +	for_each_present_cpu(cpu) {
> +		data = &per_cpu(dm_cpu_data, cpu);
> +		del_timer(&data->send_timer);
> +		cancel_work_sync(&data->dm_alert_work);
> +		/*
> +		 * At this point, we should have exclusive access
> +		 * to this struct and can free the skb inside it
> +		 */
> +		kfree_skb(data->skb);
> +	}
> +

I dont think for_each_present_cpu(cpu) is right 

(I realize drop_monitor already uses this, but its a bug)

To use it, you must have a notifier to react to cpu HOTPLUG events.

-> for_each_possible_cpu() is more correct.

Also, please dont add new printk(KERN_WARNING ...), use pr_warn(...)
instead