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Date: Thu, 21 Feb 2008 23:24:18 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: Jens Axboe <jens.axboe@oracle.com>
Subject: Re: [BUG] Linux 2.6.25-rc2 - Regression from 2.6.24-rc1-git1
	softlockup  while bootup on powerpc
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On Tue, 19 Feb 2008 09:36:34 +0100 Jens Axboe <jens.axboe@oracle.com> wrote:

> But I think the radix 'scan over entire tree' is a bit fragile.

eek, it had better not be.  Was this an error in the caller?  Hope so.

> This
> patch adds a parallel hlist for ease of properly browsing the members,

Even though io_contexts are fairly uncommon, adding more stuff to a data
structure was a pretty sad alternative to fixing a bug in
radix_tree_gang_lookup(), or to fixing a bug in a caller of it.

IOW: what exactly went wrong here??