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Date:      Sun, 07 Jul 2013 11:50:29 +0300
From:      Daniel Braniss <danny@cs.huji.ac.il>
To:        Jeremy Chadwick <jdc@koitsu.org>
Cc:        "freebsd-stable@freebsd.org Stable" <freebsd-stable@freebsd.org>, Dimitry Andric <dim@FreeBSD.org>
Subject:   Re: make buildworld is now 50% slower
Message-ID:  <E1Uvkft-0007jb-O6@kabab.cs.huji.ac.il>
In-Reply-To: <20130705145839.GB5449@icarus.home.lan>
References:  <E1Uv1lv-0000wY-9K@kabab.cs.huji.ac.il>  <CE93BC6C-31DE-4549-B257-004D3DFE4294@FreeBSD.org>  <20130705145839.GB5449@icarus.home.lan>

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> On Fri, Jul 05, 2013 at 02:39:00PM +0200, Dimitry Andric wrote:
> > [redirecting to the correct mailing list, freebsd-stable@ ...]
> > 
> > On Jul 5, 2013, at 10:53, Daniel Braniss <danny@cs.huji.ac.il> wrote:
> > > after today's update of 9.1-STABLE I noticed that make build[world|kernel] are
> > > taking conciderable more time, is it because the upgrade of clang?
> > > and if so, is the code produced any better?
> > > 
> > > before:
> > > buildwordl:	 26m4.52s real 2h28m32.12s user 36m6.27s sys
> > > buildkernel:	 7m29.42s real 23m22.22s user 4m26.26s sys
> > > 
> > > today:
> > > buildwordl:	34m29.80s real 2h38m9.37s user 37m7.61s sys
> > > buildkernel:    15m31.52s real 22m59.40s user 4m33.06s sys
> > 
> > Ehm, your user and sys times are not that much different at all, they
> > add up to about 5% slower for buildworld, and 1% faster for build kernel.
> > Are you sure nothing else is running on that machine, eating up CPU time
> > while you are building? :)
> > 
> > But yes, clang 3.3 is of course somewhat larger than 3.2.  You might
> > especially notice that, if you are using gcc, which is very slow at
> > compiling C++.
> > 
> > In any case, if you do not care about clang, just set WITHOUT_CLANG= in
> > your /etc/src.conf, and you can shave off some build time.
> 
> I just built world/kernel (stable/9 r252769) 5 hours ago.  Results:
> 
> time make -j4 buildworld  = roughly 21 minutes on my hardware
> time make -j4 buildkernel = roughly 8 minutes on my hardware
> 

It's been a long time since I saw such numbers, maybe it's time
to see where time is being spent, I will run it without clang to compare with
your numbers.

> These numbers are about the norm for me, meaning I do not see a
> substantial increase in build times.
> 
> Key point: I do not use/build/grok clang, i.e. WITHOUT_CLANG=true is in
> my src.conf.  But I am aware of the big clang change in r252723.
> 
> If hardware details are wanted, ask, but I don't think it's relevant to
> what the root cause is.
> 

from what you are saying, I guess clang is not responsible.
looking for my Sherlock Holmes hat.
thanks,
	danny

> -- 
> | Jeremy Chadwick                                   jdc@koitsu.org |
> | UNIX Systems Administrator                http://jdc.koitsu.org/ |
> | Making life hard for others since 1977.             PGP 4BD6C0CB |
> 





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