Re: building netbsd-9 2 'sync' processes stuck in 'tstile'

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Sat, 8 May 2021 15:26:35 -0500 (CDT)
    From:        "John D. Baker" <jdbaker%consolidated.net@localhost>
    Message-ID:  <Pine.NEB.4.64.2105081515550.1246%spike.technoskunk.fur@localhost>

  | This is RAID-R (RAID-5 w/rotated sparing).

OK, doesn't look to be filesystem (content)
related anyway.

  | I know I can run 'crash' at any time,
  | but I'd prefer to not risk upsetting
  | anything if a problem occurs.

The point was that (without -w) crash is
as safe as ls or grep (etc).   It can be
difficult to get results in some cases,
as the system is changing faster than crash
can possibly keep up, but here the data in
question was all very stable (nothing moving
at all) so that would not have been an issue.

Then from your later message, the reply
to Greg Woods...

  | trace: pid 2923 lid 1 at 0xffff810060d26e80
  | sleepq_block() at sleepq_block+0x19a
  | turnstile_block() at turnstile_block+0x2de
  | mutex_vector_enter() at mutex_vector_enter+0x2b4
  | do_sys_sync() at do_sys_sync+0x45
  | sys_sync() at sys_sync+0x9
  | syscall() at syscall+0x157
  | --- syscall (number 36) ---

That's the mountpoint lock (mnt_updating).
sync iterates over all mounted filesystems
performing a fikesystem dependant sync on
each.  It would have been nice to look and
see which one was locked and never being
released.   

I don't suppose you know exactly what was
mounted before the reboot?
It would only be guessing at this point
but perhaps someone might recognise a
potential problem.

And from the most recent (at least that I
have seen) message:

  | As expected, the shutdown procedure got stuck:
  | I waited about fifteen minutes

That was plenty long enough.

  | Afterward, the RAID configured and the
  | parity re-write was almost instantaneous.
  | 'fsck -yf' revealed no faults.

Most likely all the important filesystems
sync'd cleanly, and about all that did not
happen was raid being marked clean.

  | At this point I rebooted again and booted
  | a -current kernel which

Are you still running that, or back to -9 ?

  | I've asked that it be pulled up to netbsd-9.

Yes, saw that.

kre