Exactly that commit (was Re: Latest -current 100% hang at the late boot stage)

[Andrey Chernov]

On Thu, Jun 23, 2011 at 03:51:36PM +0300, Andriy Gapon wrote:
> More than once I've seen under qemu that the kernel boot non-deterministically
> gets stuck in the cd driver.  Other people have also bumped into this.
> E.g., here's one of the reports that I googled up, it's not exactly the same as
> what ache has reported, but somewhat similar:
> http://lists.freebsd.org/pipermail/freebsd-current/2010-October/020336.html

>Thread named as "xpt_thrd" might be of particular interest.
See my reply to ken (after applying recent r223443), "caplck" 
seems gone, but xpt_thrd waiting forever in "ccb_scan" with repeated 
messages:
run_interrupt_driven_hooks: still waiting after XXX seconds for xpt_config

-- 
http://ache.vniz.net/