Date: Wed, 23 Jul 2003 00:17:24 +1000 (EST) From: Bruce Evans <bde@zeta.org.au> To: Poul-Henning Kamp <phk@phk.freebsd.dk> Cc: cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/dev/lnc if_lnc.c Message-ID: <20030722235600.X8165@gamplex.bde.org> In-Reply-To: <10036.1058870835@critter.freebsd.dk> References: <10036.1058870835@critter.freebsd.dk>
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On Tue, 22 Jul 2003, Poul-Henning Kamp wrote:
> In message <20030722104524.GA80471@survey.codeburst.net>, Paul Richards writes:
> >On Tue, Jul 22, 2003 at 02:22:00AM -0700, Poul-Henning Kamp wrote:
> >> phk 2003/07/22 02:22:00 PDT
> >>
> >> FreeBSD src repository
> >>
> >> Modified files:
> >> sys/dev/lnc if_lnc.c
> >> Log:
> >> Don't inline ridiculously very large functions.
> >>
> >> Compared to the contents of these functions, an extra function call
> >> is nano-peanuts.
> >
> >Both of those functions were called from just one place, inside the
> >interrupt handler. Is there any reason to not inline them?
>
> Yes, we need to get -Werror on the kernel again, and GCC whines about
> ridiculously large functions.
I think you mean "gcc emits the requested diagnostic about functions that
it doesn't inline, whether they are large or small".
Just turn off -Winline to not request this diagnostic.
> Inline should not be used unless it has a measurable impact on
> performance.
Several places, including if_lnc.c, used __inline to get cleaner code
at no cost in performance. Removing __inline adds a tiny cost.
I build RELENG_3, RELENG_4, -current, and my version of old version of
-current all with the -current gcc. I only turned off -Winline for
my version of -current since -Werror isn't on in the others. The number
of inlining failures for a kernel with similar features but unsimilar
bloat is:
RELENG_3: 19 (15 for writertc in clock.c)
RELENG_4: 39 (18 for writertc in clock.c)
-current: 3167 (the leaf inlines haven't changed that much, but the bloat
around them has)
-my-not-very-current: ? (see no evil)
Bruce
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