Newer BSD thingies....nice but then again....

Thor Lancelot Simon tls at rek.tjls.com
Sat Jun 10 04:59:38 AEST 2000


On Fri, Jun 09, 2000 at 07:53:05PM +0200, Johnny Billquist wrote:
> > 
> > My experience with compilers on the VAX leads me to believe that the
> > substantial "savings" seen over NetBSD or post-4.3 BSD distributions here
> > is almost entirely due to the compiler and options used.  If Quasijarus
> > builds like CSRG 4.3 did, with pcc, it can't even use the optimizer *at all*
> > for the kernel build, due to severe bugs; either way, pcc runs a lot faster
> > than gcc though it generates code that runs a whole lot slower.
> 
> Um. Let me put it this way... Userland is a *lot* smaller in 4.3 than
> NetBSD... How much time do you think that makes up? The same goes for the
> kernel. It's not that 4.3 is faster per se, just that it has a lot less to
> build.

Well, of course it does.  But it's also well worth keeping in mind that
while pcc is generally inferior to gcc in almost every other way, due
to its simplicity it *is* probably at least five times as fast.  A lot
of the difference in speed we're talking about here, particularly
with regard to the kernel, is due to the use of a much slower compiler;
as much of the kernel as you *have* to build for a VAX (as opposed to
what you *can* build if you *want to*) hasn't really bloated a lot
between 4.3 and NetBSD.  Runtime memory use is a somewhat different
matter, but we do still fit into Ragge's smaller VAXen pretty well.

Thanks to Michael for reminding me exactly what the situation with
the optimizer and kernel builds under 4.3 is.  Though I think he
forgot to mention "inline" (ack!  pffffft!)... :-)

-- 
Thor Lancelot Simon	                                      tls at rek.tjls.com
	"And where do all these highways go, now that we are free?"

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