Re: VAX static vs dynamic performance

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

On 24 April 2014 09:08, Johnny Billquist <bqt%update.uu.se@localhost> wrote:
> On 2014-04-24 07:58, Anders Magnusson wrote:
>>
>> David Brownlee skrev 2014-04-24 00:47:
>>>
>>> I thought I'd test the static vs dynamic netbsd-6 install on simh (on
>>> my T420s thinkpad). Unfortunately (or fortunately depending on your
>>> view) the numbers do not seem to be significant.
>>>
>>> Timed by hand, repeated a couple of times:
>>>
>>>  From completion of kernel load sizes line until login prompt
>>> - dynamic: ~58 sec
>>> - static: ~56 sec
>>>
>>> Login as root with empty password, from RETURN to # prompt
>>> - dynamic: ~19 sec
>>> - static: ~18 sec
>>>
>> Thanks for testing this.  Only a few % slower would be expected, since
>> there is not much difference between PIC and non-PIC code on vax.
>
> Well, there is more than just PIC as a difference. With dynamic executables,
> you have to open dynamic libraries, load them into memory at runtime,
> resolve symbols, and so on, which have been suggested in the past to be a
> big source of the slowdown. It would now seem that is not the case, so it
> really is something done in the kernel that have gotten way slower.

There is also a large caveat that this was run on simh, so the timings
should be taken as "probably indicative". They could be significantly
different on real hardware.

I do agree that its likely that the main issue lies elsewhere.