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

[Andrey Chernov]

On Fri, Jun 24, 2011 at 04:20:24PM -0400, Justin T. Gibbs wrote:
> Instead, I believe that either one of the GEOM taste methods is leaking an
> access reference (so cdclose() is not called), or the CD driver is failing
> to release the hold semaphore during probing.  Setting kern.geom.debugflags
> to '4' will trace the access calls and allow the GEOM side to be ruled out.
> If GEOM is exonerated, we can add tracing to cam_perihp_(un)hold to track
> this down further.

No problem. I just set kern.geom.debugflags=4 in loader.conf and here is 
new photo (with recent kernel, no patches):
http://img803.imageshack.us/img803/4679/25062011006.jpg
I skip all noisy parts related to ada0 and ada1 partitions probes.
As you can see, only 3 cd0-related geom call issued, right before cd1 
probe shown. Strange thing is that I see no single cd1-related geom 
call, but it may be because of hang.

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