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Date: Mon, 11 Feb 2013 14:22:21 -0800
From: Steve Kargl <sgk@troutmask.apl.washington.edu>
To: David Chisnall <theraven@FreeBSD.org>
Subject: Re: 7+ days of dogfood
Message-ID: <20130211222221.GA83846@troutmask.apl.washington.edu>
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 <20130211114811.09e56b55@fabiankeil.de>
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On Mon, Feb 11, 2013 at 01:29:12PM +0000, David Chisnall wrote:
> On 11 Feb 2013, at 10:48, Fabian Keil <freebsd-listen@fabiankeil.de> wrote:
> 
> > It's unfortunate that the builworld time roughly trippled since
> > 2010 but I guess that's progress and a more powerful system
> > should fix it. I certainly welcome clang in general, though.
> 
> In that case, it's worth noting that you can shave a fair bit off
> the build time by not building gcc.  WITHOUT_GCC=yes in src.conf
> is worthwhile.
> 

While not building a part of the base system will obviously
speed up bulidworld, it seems to me that you're being a
little too generous here.  The buildworld-speed issue is
clearly a problem with clang/llvm.  On my very lightly
loaded, 4-core opteron system with 16 GB of memory, I see

WITH_CLANG="YES"
WITH_GCC="YES"

rm -rf /usr/obj/*
time make -j4 buildworld
3634.55 real      9784.21 user      1286.08 sys

WITH_CLANG="YES"
WITHOUT_GCC="YES"

rm -rf /usr/obj/*
time make -j4 buildworld
3489.40 real      9413.90 user      1324.72 sys

WITHOUT_CLANG="YES"
WITH_GCC="YES"

rm -rf /usr/obj/*
time make -j4 buildworld
1928.38 real      5254.85 user      1075.68 sys

-- 
Steve