From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Morton <akpm@osdl.org>
Subject: Re: [Patch 6/6] per task delay accounting taskstats interface: fix
 clone skbs for each listener
Date: Tue, 11 Jul 2006 03:05:24 -0700
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On Tue, 11 Jul 2006 00:36:39 -0400
Shailabh Nagar <nagar@watson.ibm.com> wrote:

>  	down_write(&listeners->sem);
>  	list_for_each_entry_safe(s, tmp, &listeners->list, list) {
> -		ret = genlmsg_unicast(skb, s->pid);
> +		skb_next = NULL;
> +		if (!list_islast(&s->list, &listeners->list)) {
> +			skb_next = skb_clone(skb_cur, GFP_KERNEL);

If we do a GFP_KERNEL allocation with this semaphore held, and the
oom-killer tries to kill something to satisfy the allocation, and the
killed task gets stuck on that semaphore, I wonder of the box locks up.

Probably it'll work out OK if the semaphore is taken after that task has
had some resources torn down.