Re: Small MicroVAX IIs - what version? - was Re: NetBSD/vax current

[David Brownlee <abs%netbsd.org@localhost>]

It would be nice if there were numbers for the relative performance of
NetBSD versions.
I've alluded to this before, and I'd be happy to collect them, but the
only machines supported by 1.2 were the uVAXII and 11/750, and I only
have a 4000 and a VS2000. (*)

I think the idea test box would be a 16M uVAXII, though a smaller RAM
size would also be helpful.

Since NetBSD (usually) provides excellent backwards compatibility it
should be possible to install NetBSD 1.2, run some timings, and then
retest the same install with a kernel from 1.3, 1.4, 1.5...
(There may be a version which requires new boot blocks, but the
principle applies).

That first pass would determine how kernel code bloat has affected the
system over time.

The second pass would be be similar, but reinstalling the entire
system rather than kernel each time.

One key point would be to determine a useful set of tests - lmbench,
apachebench against a simple http server, and a nasty shell script?

I know that gcc bloat makes it effectively unusable on anything but
the largest memory/fastest VAXes now day, but it would be helpful to
determine what has happened to baseline NetBSD performance...

David

(* If someone has a spare uVAXII in the UK I'd be delighted to give it
a loving home, but I'm not trying to use the above as an excuse to pry
one out of an existing home.... well, not really :)

On 13 April 2014 22:23, Johnny Billquist <bqt%update.uu.se@localhost> wrote:
> On 2014-04-13 23:12, Toby Thain wrote:
>>
>> On 13/04/14 4:35 PM, John Klos wrote:
>>>>
>>>> I'm going to try and do some more testing, but I really can't see many
>>>> other explanations. I noticed that just booting NetBSD up on the
>>>> 4000/90 grabbed more than 16M before the boot was complete, so with
>>>> only 16M it is going to be paging a lot.
>>>
>>>
>>> NetBSD 6 runs OK on a VAXstation 4000/30 with 24 megs. Not great, but OK.
>>>
>>
>> Any recommendations for a MicroVAX II with 9MB? I have 1.4.1 netbooting
>> on it right now and it's pretty happy - was able to compile Apache
>> 1.3.x, etc.
>>
>> Is 1.5 okay for such a small system? I've read conflicting opinions.
>
>
> If you ask me, 1.6 is just fine as well. 2.0 is still also pretty ok. I'm
> not sure exactly when things became horrible, but back in those versions,
> NetBSD was still pretty snappy, as far as I can remember. (Used to run a
> VAX-11/750 with it, and still thought it was acceptable.)
>
> On another side note, NetBSD/vax (but I sortof notice something similar on
> other architectures) are hitting the namei sys-cache a lot. And when that
> happens, the system is spending the majority of the time in system, and are
> not making much progress on anything.
> There seems to be a very clear correspondence between the namei calls and
> the amount of time spent in system. With gcc just chugging along trying to
> compile a file, I see maybe 1000 namei calls in 5s (looking at system). With
> this, I have about 10% system time. When namei calls jumps to above 6000 I
> have more than 50% time in system, sometimes going up to over 80%. The
> correlation is not absolute, but there definitely seems to be some
> connection between them.
>
> I recently fired up an Alpha with current, and sometimes the namei calls
> jumps up to over 100.000, which I found rather impressive. (Although maybe
> also depressing.) And of course, that machine also spent large chunks of
> time in system.
>
>
>>> http://vax.zia.io/
>>>
>>> The hardware isn't as cool as an 11/785, but it's a bit more affordable
>>> to run :)
>>>
>>>
>>>>>    Well, get to it, man! ;)  I expect there will eventually be a
>>>>> fork of
>>>>> NetBSD that will trim the fat and make it more usable.  Testing on
>>>>> older, slower hardware would go a long way toward "keeping it honest".
>>>>
>>>>
>>>> Question is if anyone have the time, energy and money for that to
>>>> happen?
>>>
>>>
>>> It'd be nice to see pcc for VAX instead of gcc. gcc has way too much fat
>>> and take way too long to do anything. And I wonder how much better an
>>> entirely crunchgen'd NetBSD would be on a very low memory machine...
>>
>>
>> I wonder if lcc does a better job than pcc. lcc is ANSI and has a VAX
>> code generator, that's fairly easy to modify.
>>
>> https://sites.google.com/site/lccretargetablecompiler/
>
>
> I think that Ragge have gotten pcc more or less to compile most of NetBSD,
> so ANSI is not a problem.
>
>         Johnny
>
> --
> 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