From owner-freebsd-stable Thu Sep 20 8:36:29 2001 Delivered-To: freebsd-stable@freebsd.org Received: from smtprelay3.abs.adelphia.net (smtprelay.abs.adelphia.net [64.8.20.11]) by hub.freebsd.org (Postfix) with ESMTP id 8D69937B411 for ; Thu, 20 Sep 2001 08:35:46 -0700 (PDT) Received: from there ([63.88.159.67]) by smtprelay3.abs.adelphia.net (Netscape Messaging Server 4.15) with SMTP id GJYWNI02.5W4; Thu, 20 Sep 2001 11:35:42 -0400 Content-Type: text/plain; charset="iso-8859-1" From: Gerald A.Speak Reply-To: gaspeak@va.prestige.net To: clefevre@citeweb.net, Erik Trulsson Subject: Re: make -j4 vs -j8... 4 works, but 8 does not Date: Thu, 20 Sep 2001 11:35:44 -0400 X-Mailer: KMail [version 1.3] Cc: stable@FreeBSD.ORG References: <200109170009.f8H09Y921584@gits.dyndns.org> In-Reply-To: <200109170009.f8H09Y921584@gits.dyndns.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Message-Id: <20010920153546.8D69937B411@hub.freebsd.org> Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Sunday 16 September 2001 08:09 pm, Cyrille Lefevre wrote: > Erik Trulsson wrote: > > On Sat, Sep 15, 2001 at 06:06:10PM -0400, Garance A Drosihn wrote: > > > [aside on those multiple builds that I did: It was interesting that > > > even though it was on a dual-processor system, there was not much of > > > a speed improvement (on 4.3-stable) when going from -j4 to -j10. Big > > > improvement going from -j1 to -j4, but after that it didn't help much] > > > > That sounds exactly like what I would expect. More than 2 (or maybe 3) > > jobs per CPU is normally not going to make things go faster but might > > actually slow it down. > > I'm not right w/ you. let's try : > > # setup a reusable environment > cd /sys/compile/MYKERNEL > make depend > make > # run the jobs > for i in 1 2 4 8; do > (date;touch opt_global.h;time make -j$i all;date) >| .j$i 2>&1 > done > > results are (on my old P200 processor) : > > j1 12:36 > j2 12:46 > j4 11:36 > j8 11:21 > > so, for a 12 min job, you could win 1 min using -j4, which may gives > you 1 hour for a 12 hours job (such as buildworld :). ok, it's not so > many, but that may help a lot. for instace, I currently use -j4 since > -j8 is too CPU and memory intensive (the machine slow down significally). > > PS : I'm using SCSI disks. using IDE disks probably gives you different > results. I/O are very differents between the two. > > Cyrille. I had some time to spend and came up with the following results for doing make build world. Before each build I made sure that /usr/obj/ was empty. time make buildworld... 1800.325u 818.652s 44:35.38 97.8% 1322+1456k 9130+5803io 555pf+0w time make -j 2 buildworld ... 1852.919u 957.381s 44:09.71 106.0% 1305+1471k 9231+5677io 555pf+0w time make -j 4 buildworld ... 1881.497u 965.330s 36:17.07 130.7% 1314+1472k 9307+6329io 626pf+0w time make -j 6 buildworld ... 1884.092u 973.077s 35:25.23 134.4% 1314+1473k 9246+6096io 555pf+0w time make -j 8 buildworld ... 1879.997u 977.772x 35:27.64 134.3% 1310+1469k 9240+6310io 555pf+0w As you can see there was only a matter of a couple minutes improvement when using -j 8 instead of -j 4. The build machine is a Dual PIII 1000, with 1GB RAM and SCSI Ultra160 Drive (too bad FreeBSD only runs the Adaptec 29160N at 80MHz. dmesg below for those interested. Copyright (c) 1992-2001 The FreeBSD Project. Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994 The Regents of the University of California. All rights reserved. FreeBSD 4.4-STABLE #0: Thu Sep 20 10:17:57 EDT 2001 gaspeak@sampson.gaspeak-p-va.prestige.net:/usr/obj/usr/src/sys/SAMPSON Timecounter "i8254" frequency 1193182 Hz CPU: Pentium III/Pentium III Xeon/Celeron (1004.50-MHz 686-class CPU) Origin = "GenuineIntel" Id = 0x68a Stepping = 10 Features=0x383fbff real memory = 1073725440 (1048560K bytes) config> q avail memory = 1041256448 (1016852K bytes) Programming 24 pins in IOAPIC #0 IOAPIC #0 intpin 2 -> irq 0 FreeBSD/SMP: Multiprocessor motherboard cpu0 (BSP): apic id: 3, version: 0x00040011, at 0xfee00000 cpu1 (AP): apic id: 0, version: 0x00040011, at 0xfee00000 io0 (APIC): apic id: 2, version: 0x00178011, at 0xfec00000 Preloaded elf kernel "kernel" at 0xc0464000. Preloaded userconfig_script "/boot/kernel.conf" at 0xc046409c. Preloaded elf module "splash_bmp.ko" at 0xc04640ec. Preloaded elf module "vesa.ko" at 0xc0464190. Preloaded splash_image_data "/boot/splash.bmp" at 0xc046422c. Preloaded elf module "vn.ko" at 0xc046427c. Preloaded elf module "snd_es137x.ko" at 0xc0464318. Preloaded elf module "snd_pcm.ko" at 0xc04643bc. Preloaded elf module "usb.ko" at 0xc046445c. Preloaded elf module "ugen.ko" at 0xc04644f8. Preloaded elf module "uhid.ko" at 0xc0464594. Preloaded elf module "ulpt.ko" at 0xc0464630. Preloaded elf module "ums.ko" at 0xc04646cc. Preloaded elf module "umass.ko" at 0xc0464768. Preloaded elf module "uscanner.ko" at 0xc0464808. Preloaded elf module "agp.ko" at 0xc04648a8. Preloaded elf module "vpo.ko" at 0xc0464944. VESA: v3.0, 16384k memory, flags:0x1, mode table:0xc0338437 (1000117) VESA: 3dfx Interactive, Inc. Pentium Pro MTRR support enabled md0: Malloc disk Using $PIR table, 7 entries at 0xc00f12d0 npx0: on motherboard npx0: INT 16 interface pcib0: on motherboard IOAPIC #0 intpin 18 -> irq 2 IOAPIC #0 intpin 17 -> irq 5 IOAPIC #0 intpin 16 -> irq 9 IOAPIC #0 intpin 19 -> irq 10 pci0: on pcib0 agp0: mem 0xf8000000-0xfbffffff at device 0.0 on pci0 pcib2: at device 1.0 on pci0 pci1: on pcib2 pci1: <3Dfx Voodoo 3 graphics accelerator> at 0.0 irq 9 isab0: at device 4.0 on pci0 isa0: on isab0 atapci0: port 0xb800-0xb80f at device 4.1 on pci0 ata0: at 0x1f0 irq 14 on atapci0 ata1: at 0x170 irq 15 on atapci0 uhci0: port 0xb400-0xb41f irq 2 at device 4.2 on pci0 usb0: on uhci0 usb0: USB revision 1.0 uhub0: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr 1 uhub0: 2 ports with 2 removable, self powered uhub1: Microsoft product 0x001c, class 9/0, rev 1.10/5.00, addr 2 uhub1: 3 ports with 2 removable, bus powered uhci1: port 0xb000-0xb01f irq 2 at device 4.3 on pci0 usb1: on uhci1 usb1: USB revision 1.0 uhub2: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr 1 uhub2: 2 ports with 2 removable, self powered pci0: (vendor=0x11d1, dev=0x01f7) at 10.0 irq 2 pcm0: port 0xa800-0xa83f irq 5 at device 11.0 on pci0 de0: port 0xa400-0xa47f mem 0xf1000000-0xf100007f irq 9 at device 12.0 on pci0 de0: 21140A [10-100Mb/s] pass 2.2 de0: address 00:40:05:a2:d8:ea ahc0: port 0xa000-0xa0ff mem 0xf0800000-0xf0800fff irq 10 at device 13.0 on pci0 aic7892: Ultra160 Wide Channel A, SCSI Id=7, 32/255 SCBs pcib1: on motherboard pci2: on pcib1 orm0: