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Date: Tue, 25 Apr 2006 00:56:54 -0700
From: Andrew Morton <akpm@osdl.org>
To: "Bryan O'Sullivan" <bos@pathscale.com>
Cc: rdreier@cisco.com, openib-general@openib.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 8 of 13] ipath - fix a number of RC protocol bugs
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"Bryan O'Sullivan" <bos@pathscale.com> wrote:
>
> +	BUG_ON(qp->timerwait.next != LIST_POISON1);
>  +	list_add_tail(&qp->timerwait, &dev->pending[dev->pending_index]);

Please don't play around with list_head internals like this - some
speedfreak might legitimately choose to remove the list_head poisoning
debug code, or make it Kconfigurable.

One option would be to always do list_del_init() on this thing, then do
BUG_ON(!list_empty()).