Kernel hang r247079 mps/vfs/zfs?

[Steve Wills]

Hi,

> I was testing a patch on r246300 or so, and wanted to see if it would
> apply
> cleanly to a newer copy of HEAD.
>
> Well it did, except I had a hang at boot, shortly after ZFS version and
> the
> last scsi devices appear.
> This easily could have been related to the patch I was testing, so I wiped
> /usr/src/ and /usr/obj (after booting kernel.old) and rebuilt world and
> kernel cleanly.
>
> I assumed that would resolve the issue, but it did not.
>
> The hang happens right after zfs is announced, and the last da devices
> (some of which are usb) are reported. It comes before the noisy output of
> mps.
>
> Hang is complete, and single user or verbose don't yield much.
>
> I'm having trouble exfiltrating a dmesg from it, but it may be unrelated
> to
> the userland issues reported earlier, as single user does not resolve it
> for me.
> The svn up was at 11:20 pacific (GMT +8).
>
> Anyone else seeing similar issues?
>
> Hardware is an LSI mps device, "9210" crossflashed m1015. Pool is a zfs
> mirror. Works fine booting from r246300 kernel.
> Motherboard is an AMD Tyan.
> Pulling USB headers off the board didn't resolve it.

I am experiencing a similar hang when updating from r246190 to r247017 on
my all zfs system. The system has two drives in a zfs mirror and hangs
after detecting the hard drives. The last thing seen is the "ada1:
Previously was known as ad8" message, then it hangs completely, unable to
even ctrl-alt-del or even get the numlock key to toggle the light. System
is:

CPU: AMD Phenom(tm) II X4 955 Processor (3214.39-MHz K8-class CPU)

with ASUS M4A78LT-M board. Let me know if other details will help.

Steve