Re: head -r331499 amd64/threadripper panic in vm_page_free_prep during "poudriere bulk -a", after 14h 22m or so.

On 2018-Mar-25, at 1:09 PM, Mark Johnston <markj at FreeBSD.org> wrote:

> On Sun, Mar 25, 2018 at 12:32:09PM -0700, Mark Millard wrote:
>> On 2018-Mar-25, at 11:34 AM, Mark Johnston <markj at FreeBSD.org> wrote:
>> 
>>> On Sun, Mar 25, 2018 at 10:41:38AM -0700, Mark Millard wrote:
>>>> FreeBSD panic'd while attempting to see if a "poudriere bulk -w -a"
>>>> would get the "unnecessary swapping" problem in my UFS-only context,
>>>> -r331499 (non-debug but with symbols), under Hyper-V. This is a
>>>> Ryzen Threadripper context, but I've no clue if that is important
>>>> to the problem. This was after 14 hours or so of building:
>>>> 
>>>> . . .
>>>> [14:22:05] [18] [00:01:16] Finished devel/p5-Test-HTML-Tidy | p5-Test-HTML-Tidy-1.00_1: Success
>>>> [14:22:08] [18] [00:00:00] Building devel/ocaml-camlp5 | ocaml-camlp5-6.16
>>>> 
>>>> So I've no clue if or how to repeat this.
>>>> 
>>>> Unfortunately dump was unsuccessful. 
>>> 
>>> What happened?
>> 
>> It reported:
>> 
>> (da1:strovsc1:0:0:0) WRITE(10). CDB 2a 00 35 24 37 c7 00 00 0 00
>> (da1:storvsc1:0:0:0) CAM status Command timeout
>> (da1:storvsc1:0:0:0) Error 5, Retries exhausted
>> Aborting dump to to I/O error.
>> 
>> ** DUMP FAILED (ERROR 5) **
>> = 0x5
> 
> Thanks. Do you happen to know if this occurs consistently under Hyper-V?

For both "this" being (A) the panic and (B) the attempt
to dump to the Optane SSD that holds the swap/page partition:

First ever occurrence of the activity, so nothing to compare
with.

The system sat at the db> prompt for a notable time while I
was sleeping. It kept its "cores" busy while I slept. (Hardware
threads being very active is visible from Windows 10 Pro x64's
Task Manager.)

It is rare that I try such a large bulk build. I do such mostly
just to test how well the Ryzen Threadripper context seems to be
doing or to otherwise test something about FreeBSD stability.
I do buildworld buildkernel for such testing as well. Sometimes
both poudriere ports-building and FreeBSD-building in parallel
for a time.

I have started "poudriere bulk -j<NAME> -w -a" again, letting
it continue from where it left off.

>>>> So all I have is the
>>>> backtrace. Hand typed from a screen shot of the console
>>>> window:
>>> 
>>> Do you know what the panic message was? There are multiple calls to
>>> panic() in vm_page_free_prep().
>> 
>> No. I listed what I could see. The console screen does not have many
>> lines or rows and I was sleeping when the panic happened.
> 
> For future reference, you should be able to use "show panic" at the DDB
> prompt to get the panic message.

Dahhhh. Too obvious of a thing for me to think of checking for such on
my own. At least now I know. (It is not the first time that I could have
used that command.)

===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)