Re: "panic: Unholding 5 with cnt = 0" head/amd64 _at_r331290

i've reverted r331273. In trying to fix the too many refs problem, I
created the too few refs problem.

Warner

On Wed, Mar 21, 2018 at 6:26 AM, Roman Bogorodskiy <novel_at_freebsd.org>
wrote:

>   David Wolfskill wrote:
>
> > This is on my build machine, running a GENERIC kernel.  (Laptop is still
> > building lib32 shim libraries as I type).
> >
> > Here's a copy/paste from the serial console:
> >
> > da3: Attempt to query device size failed: NOT READY, Medium not present
> > da3: quirks=0x2<NO_6_BYTE>
> > da3: Delete methods: <NONE(*),ZERO>
> > GEOM: new disk da1
> > GEOM: new disk da2
> > GEOM: new disk da3
> > (da1:umass-sim0:0:0:1): PREVENT ALLOW MEDIUM REMOVAL not supported.
> > ugen0.4: <Broadcom Corp BCM43142A0> at usbus0
> > (dpanic: Unholding 5 with cnt = 0
> > cpuid = 3
> > time = 1521633742
> > KDB: stack backtrace:
> > db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame
> 0xfffffe00004913c0
> > vpanic() at vpanic+0x18d/frame 0xfffffe0000491420
> > panic() at panic+0x43/frame 0xfffffe0000491480
> > dadone() at dadone+0x1cc9/frame 0xfffffe00004919e0
> > xpt_done_process() at xpt_done_process+0x390/frame 0xfffffe0000491a20
> > xpt_done_td() at xpt_done_td+0xf6/frame 0xfffffe0000491a70
> > fork_exit() at fork_exit+0x84/frame 0xfffffe0000491ab0
> > fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe0000491ab0
> > --- trap 0, rip = 0, rsp = 0, rbp = 0 ---
> > KDB: enter: panic
> > [ thread pid 15 tid 100065 ]
> > Stopped at      kdb_enter+0x3b: movq    $0,kdb_why
> > db>
> >
> >
> > Anything I can/should do to poke at it before trying to capture a dump?
>
> Looks like it's related to:
>
> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=226510#c18
>
> > Peace,
> > david
> > --
> > David H. Wolfskill                            david_at_catwhisker.org
> > An investigator who doesn't make a perp nervous isn't doing his job.
> >
> > See http://www.catwhisker.org/~david/publickey.gpg for my public key.
>
>
>
> Roman Bogorodskiy
>