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Date:      Thu, 28 Nov 1996 16:03:16 -0500 (EST)
From:      "John S. Dyson" <toor@dyson.iquest.net>
To:        joerg_wunsch@uriah.heep.sax.de
Cc:        freebsd-current@FreeBSD.org
Subject:   Re: inlining (Was: users of "ft" tapes...)
Message-ID:  <199611282103.QAA03782@dyson.iquest.net>
In-Reply-To: <199611282005.VAA16339@uriah.heep.sax.de> from "J Wunsch" at Nov 28, 96 09:05:02 pm

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> As Poul-Henning Kamp wrote:
> 
> > >I have been thinking about un-inlining spls.  This saves 29K out of
> > >1096K text.  It may even save some time
> 
> > I generally use the rule of thumb that unless the text-size is
> > smaller as a result, then inlining is wrong.
> 
> This is hard to achieve.  I think inlining is first aimed at
> optimizing for speed, not for size.
> 
Sometimes speed == size.  Esp, on Intel architectures with small
caches.  I would like to know if there is going to be an impact on
VM perf (which is much of what people see as perf on a machine, running
various programs, and one reason why NT is so dog slow), before un-inlining
the spl's.  If it is neutral (and that is very likely), I would be
for de-inlining also.

Note that we actually had a net microbenchmark slowdown with some of my
recent VM changes, but that had to be weighed against a speedup on
large systems (by 2x-3x.)  Most of the slowdown is probably due to the
larger data structures (and larger cache footprint.)  Alas, I am just
not able to figure out how to make some of those damned things smaller,
but if anyone does have any ideas, PLEASE PLEASE let me know.

John



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