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Date: Sat, 5 Jul 2003 11:43:08 -0700
From: Andrew Morton <akpm@osdl.org>
To: William Lee Irwin III <wli@holomorphy.com>
Cc: anton@samba.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org
Subject: Re: 2.5.74-mm1
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William Lee Irwin III <wli@holomorphy.com> wrote:
>
> The badness() check isn't good enough. If badness() returns 0 for all
>  processes with pid's > 0 and the first one seen is a kernel thread the
>  kernel thread will be chosen.

Are we looking at the same code? 

static struct task_struct * select_bad_process(void)
{
	int maxpoints = 0;
	struct task_struct *g, *p;
	struct task_struct *chosen = NULL;

	do_each_thread(g, p)
		if (p->pid) {
			int points = badness(p);
			if (points > maxpoints) {
				chosen = p;
				maxpoints = points;
			}
			if (p->flags & PF_SWAPOFF)
				return p;
		}
	while_each_thread(g, p);
	return chosen;
}

if badness() returns zero for everything, this returns NULL and
the kernel panics.