Re: netbsd-8 hang on tstile

["Aaron J. Grier" <agrier%poofygoof.com@localhost>]

On Wed, Mar 07, 2018 at 10:20:45AM +0100, J. Hannken-Illjes wrote:
> > On 6. Mar 2018, at 23:33, Manuel Bouyer <bouyer%antioche.eu.org@localhost> wrote:
> > 
> > on an up-to-date netbsd-8 Xen3 i386PAE kernel I see hangs on tstile.
> > Hung processes shows the same pattern, they sleep in fstrans_start():
> <snip>
> > 
> > This is reproductible, restarting my automatic test script hangs the
> > same way. This i plain ffs, no wapbl.
> > 
> > Any idea ?
> 
> Please enter DDB and "call fstrans_dump(0)" to see which thread blocks
> the transition (it will have "... shared N ..." with N > 0).

a pbulk build stalled out on a NetBSD-7 VM and I remembered this.  :)

db{0}> call fstrans_dump(0)
Fstrans locks by lwp:
11537.1  (/) shared 2 cow 0
Fstrans state by mount:
0
db{0}> ps
PID    LID S CPU     FLAGS       STRUCT LWP *               NAME WAIT
[...]
11537    1 3   0         0   ffffa00069efea20               find tstile
[... and a whole bunch of processes stuck in tstile ...]

-- 
  Aaron J. Grier | "Not your ordinary poofy goof." | agrier%poofygoof.com@localhost
  "The price of reliability is the pursuit of the utmost simplicity.  It
   is a price which the very rich find most hard to pay."  -- Tony Hoare