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Date:      Thu, 7 Mar 2002 16:36:15 +0100
From:      Erik Trulsson <ertr1013@student.uu.se>
To:        Peter Pentchev <roam@ringlet.net>
Cc:        mitko@rila.bg, freebsd-hackers@FreeBSD.ORG, gclarkii@vsservices.com
Subject:   Re: Swapping performance
Message-ID:  <20020307153615.GB1942@student.uu.se>
In-Reply-To: <20020307164724.D377@straylight.oblivion.bg>
References:  <20020307090707.GC26621@elvis.mu.org> <Pine.BSF.4.21.0203070359110.41354-100000@InterJet.elischer.org> <20020307142759.0d95d467.mitko@rila.bg> <20020307080906.367be8df.gclarkii@vsservices.com> <20020307164724.D377@straylight.oblivion.bg>

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On Thu, Mar 07, 2002 at 04:47:24PM +0200, Peter Pentchev wrote:
> On Thu, Mar 07, 2002 at 08:09:06AM -0600, GB Clark wrote:
> > On Thu, 7 Mar 2002 14:27:59 +0200
> > Dimitar Peikov <mitko@rila.bg> wrote:
> > 
> > > On Thu, 7 Mar 2002 04:01:58 -0800 (PST)
> > > Julian Elischer <julian@elischer.org> wrote:
> > > 
> > > > he said -stable..
> > > > 
> > > > what are the malloc options on -stable?
> > > > 
> > > > maybe we should make sure that they are null 
> > > > 
> > > > ln -s ">" /etc/malloc.conf
> > > > (I hope that helps) :)
> > > > 
> > > 
> > > I've tested it with :
> > > 
> > > cc -O6 -o malloc_test malloc_test.c
> > 
> > That -O6 does not look right from here.  Do we support anything over -O2?
> 
> ISTR that -On is exactly the same for -O2 for n > 2; or is this stale info?
> Maybe GCC 3.x supports higher optimization levels; still, I don't think
> this would make any significant difference.

n > 3 actually.  The difference between -O2 and -O3 is that -O3 enables
inlining of functions. This usually makes the generated code larger,
and sometimes faster (and sometimes slower.)

FreeBSD does not officially support anything above -O since there have
been reports of bad code generated when compiling with -O2 or higher.

(The difference in performance between -O and -O2 is usually fairly
small anyway so it doesn't matter much.)

-- 
<Insert your favourite quote here.>
Erik Trulsson
ertr1013@student.uu.se

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