Date: Sun, 7 Jul 2013 03:17:14 -0700 From: Jeremy Chadwick <jdc@koitsu.org> To: Daniel Braniss <danny@cs.huji.ac.il> 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: <20130707101714.GA51445@icarus.home.lan> In-Reply-To: <E1Uvkft-0007jb-O6@kabab.cs.huji.ac.il> References: <E1Uv1lv-0000wY-9K@kabab.cs.huji.ac.il> <CE93BC6C-31DE-4549-B257-004D3DFE4294@FreeBSD.org> <20130705145839.GB5449@icarus.home.lan> <E1Uvkft-0007jb-O6@kabab.cs.huji.ac.il>
next in thread | previous in thread | raw e-mail | index | archive | help
On Sun, Jul 07, 2013 at 11:50:29AM +0300, Daniel Braniss wrote: > > 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. Some points to those numbers I stated above: - System is an Intel Q9550 with 8GB of RAM - Single SSD (UFS2+SU+TRIM) is used for root, /usr, /var, /tmp, and swap - /usr/src is on ZFS (raidz1 + 3 disks) -- however I got equally small numbers when it was on the SSD - /usr/src is using compression=lz4 (to folks from -fs: yeah, I'm trying it out to see how much of an impact it has on interactivity. I can still tell when it kicks in, but it's way, way better than lzjb. Rather not get into that here) - Contents of /etc/src.conf (to give you some idea of what I disable): WITHOUT_ATM=true WITHOUT_BLUETOOTH=true WITHOUT_CLANG=true WITHOUT_FLOPPY=true WITHOUT_FREEBSD_UPDATE=true WITHOUT_INET6=true WITHOUT_IPFILTER=true WITHOUT_IPX=true WITHOUT_KERBEROS=true WITHOUT_LIB32=true WITHOUT_LPR=true WITHOUT_NDIS=true WITHOUT_NETGRAPH=true WITHOUT_PAM_SUPPORT=true WITHOUT_PPP=true WITHOUT_SENDMAIL=true WITHOUT_WIRELESS=true WITH_OPENSSH_NONE_CIPHER=true It's WITHOUT_CLANG that cuts down the buildworld time by a *huge* amount (I remember when it got introduced, my buildworld jumped up to something like 40 minutes); the rest probably save a minute or two at most. - /etc/make.conf doesn't contain much that's relevant, other than: CPUTYPE?=core2 # For DTrace; also affects ports STRIP= CFLAGS+= -fno-omit-frame-pointer - I do some tweaks in /etc/sysctl.conf (mainly vfs.read_min and vfs.read_max), but I will admit I am not completely sure what those do quite yet (I just saw the commit from scottl@ a while back talking about how an increased vfs.read_min helps them at Netflix quite a lot). I also adjust kern.maxvnodes. - Some ZFS ARC settings are adjusted in /boot/loader.conf (I'm playing with some stuff I read in Andriy Gapon's ZFS PDF), but they definitely do not have a major impact on the numbers I listed off. - I do increase kern.maxdsiz, kern.dfldsiz, and kern.maxssiz in /boot/loader.conf to 2560M/2560M/256M respectively, but that was mainly from the days when I ran MySQL and needed a huge userland processes. All in all my numbers are low/small because of two things: the SSD, and WITHOUT_CLANG. Hope this gives you somewhere to start/stuff to ponder. -- | Jeremy Chadwick jdc@koitsu.org | | UNIX Systems Administrator http://jdc.koitsu.org/ | | Making life hard for others since 1977. PGP 4BD6C0CB |
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20130707101714.GA51445>