Date: Tue, 22 Jan 2002 15:44:53 -0800 From: Kent Stewart <kstewart@owt.com> To: Greg Rumple <grumple@zaphon.llamas.net> Cc: freebsd-stable@FreeBSD.ORG Subject: Re: make -j4 world Message-ID: <3C4DF975.8050308@owt.com> References: <5.1.0.14.0.20020122145124.03cd1380@marble.sentex.ca> <5.1.0.14.0.20020122145124.03cd1380@marble.sentex.ca> <5.1.0.14.0.20020122151930.03d62220@marble.sentex.ca> <3C4DCB91.7080701@owt.com> <3C4DCDE7.C5E77C03@math.missouri.edu> <20020122125645.1a0c9b36.sreese@codysbooks.com> <20020122140431.R69194@zaphon.llamas.net>
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Greg Rumple wrote: > * Scott Reese (sreese@codysbooks.com) [020122 20:52]: > >>On Tue, 22 Jan 2002 14:39:03 -0600 >>Stephen Montgomery-Smith <stephen@math.missouri.edu> wrote: >> >> >>>On the "Error in make buildworld" thread I said that I had this problem >>>on 1 out of 3 machines, so you may not necessarily see this problem. I >>>only saw this problem on the fastest machine. >>> >>> >>I've actually found that on a fast computer (1.6 GHz Pentium IV) using the "-j" >>flag tends to slow things down a bit. The standard "make buildworld" ran much >>faster and much more smoothly than "make -j4 buildworld." It was the same with >>kernel builds. Honestly, with a machine that fast, I don't really see a need >>for the "-j" flags anyway. >> > > Well the machines I use make -j on are SMP machines, and using -j does > make a difference. I tend to use make -j 16 (2 p3-1Ghz cpu's, 2 gigs of > ram) in order to finish as rapidly as possible. This is significantly > faster than make by it's self. I have actually done a spreadsheet using > this machine about 6 months ago, I should do it again. Looking at the > benefit of make -j finding the optimial value. I haven't done a CVSUP > up today, so not sure if this is happening to me or not. My 4 runs with different -j looks like bw w/no -j 957.195u 263.416s 21:11.71 95.9% 1366+1576k 11744+3435io 3031pf+0w bw w/-j2 964.685u 294.253s 32:16.10 65.0% 1374+1570k 15335+3920io 1622pf+0w bw w/-j4 966.085u 298.956s 26:38.43 79.1% 1337+1536k 29343+3511io 3090pf+0w bw w/-j6 964.058u 298.116s 25:59.72 80.9% 1338+1538k 12173+3209io 2711pf+0w The no -j was the fastest by almost 4 minutes. I have a build script and I say "time mkworld" and then cat >> times.log and copy the time output line. Kent -- Kent Stewart Richland, WA mailto:kbstew99@hotmail.com http://users.owt.com/kstewart/index.html FreeBSD News http://daily.daemonnews.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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