Re: my simh-vax crashed: panic: pmap_enter on PG_SREF page

[Johnny Billquist <bqt%softjar.se@localhost>]

Nothing concrete, except that that amount of memory did have issues in 
the past. We hope it had been fixed, but maybe there is some kind of 
issue with that much memory still? Could you try with less physical 
memory? Like 128M?

  Johnny

On 2023-12-21 01:46, matthew green wrote:
> because we can't have only nice things this season, my simh crashed
> while building netbsd.
>
> this was a couple of days ago -current, built on amd64, building the
> same source tree in simh-vax.
>
> db> bt
> panic: pmap_enter on PG_SREF page
> Stack traceback :
> 0x94ba9c40: vpanic+0x179(0x802a0a35,0x94ba9cd8)
> 0x94ba9c60: vprintf+0x0(0x802a0a35)
> 0x94ba9c8c: pmap_enter+0x60a(0x8e8aec00,0x74a00000,0x2bdb000,0x3,0x21)
> 0x94ba9cf4: uvm_fault_lower_enter+0x57(0x94ba9df4,0x94ba9e10,0,0x838cc420,0x80a26d18)
> 0x94ba9d3c: uvm_fault_internal+0xd02(0x8cda5e00,0x74a00000,0x1,0)
> 0x94ba9ebc: trap+0x148(0x94ba9fb4)
> db> ps
> PID    LID S CPU     FLAGS       STRUCT LWP *               NAME WAIT
> 17504>17504 7   0     40000           8d400800            cc1plus
>
> so it was a cc1plus processing a trap, and doing what appears to be
> re-mapping a page previously mapped with pmap_kenter_pa() (the only
> way PG_SREF should be set.)
>
> this is a valid assert -- if it's been pmap_kenter_pa()'d it should
> never be otherwise managed in kernel or userspace.
>
> any one have an idea what is up?  i have ddb still for now.  this
> system is a 256mb microvax3900 instance in open-simh latest pkgsrc.
>
> thanks.
>
>
> .mrg.

--
Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: bqt%softjar.se@localhost             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol