Re: Loadavg is off-by-one

On Mon, 2004-09-06 at 21:01, Craig Reyenga wrote:
> When I run N instances of "yes > /dev/null" on my 5.3-BETA3 box (actually I
> cvsupped to RELENG_5 about a day after) I see a load average of ~N+1. When
> the system is idle, it's 0, as it ought to be.
> 
> More info upon request.
> 
> -Craig
> 
> More info:
> ULE scheduler, UP box.
> 
Running the same tests, I get a load average that slowly creeps up to N
and holds there.  This is using the 4BSD scheduler however, on a UP
box.  

My dmesg:

Copyright (c) 1992-2004 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 5.3-BETA3 #0: Sat Sep  4 19:54:16 EDT 2004
    root_at_amon.quaggaspace.org:/usr/obj/usr/src/sys/AMON
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: AMD Athlon(tm) XP 1700+ (1467.30-MHz 686-class CPU)
  Origin = "AuthenticAMD"  Id = 0x680  Stepping = 0
 
Features=0x383fbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,MMX,FXSR,SSE>
  AMD Features=0xc0400000<AMIE,DSP,3DNow!>
real memory  = 805240832 (767 MB)
avail memory = 774049792 (738 MB)
ACPI APIC Table: <KT400  AWRDACPI>
ioapic0 <Version 0.3> irqs 0-23 on motherboard
npx0: [FAST]
npx0: <math processor> on motherboard
npx0: INT 16 interface
acpi0: <KT400 AWRDACPI> on motherboard
acpi0: Power Button (fixed)
Timecounter "ACPI-fast" frequency 3579545 Hz quality 1000
acpi_timer0: <24-bit timer at 3.579545MHz> port 0x4008-0x400b on acpi0
cpu0: <ACPI CPU (3 Cx states)> on acpi0
acpi_tz0: <Thermal Zone> on acpi0
acpi_button0: <Power Button> on acpi0
acpi_button1: <Sleep Button> on acpi0
pcib0: <ACPI Host-PCI bridge> port
0x5000-0x500f,0x4080-0x40ff,0x4000-0x407f,0xcf8-0xcff on acpi0
pci0: <ACPI PCI bus> on pcib0
pcib1: <PCI-PCI bridge> at device 1.0 on pci0
pci1: <PCI bus> on pcib1
nvidia0: <GeForce4 Ti 4200 with AGP8X> mem
0xe0000000-0xe7ffffff,0xec000000-0xecffffff irq 16 at device 0.0 on pci1
nvidia0: [GIANT-LOCKED]
uhci0: <VIA 83C572 USB controller> port 0xd000-0xd01f irq 21 at device
16.0 on pci0
uhci0: [GIANT-LOCKED]
usb0: <VIA 83C572 USB controller> 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
ums0: Logitech USB-PS/2 Optical Mouse, rev 2.00/13.00, addr 2, iclass
3/1
ums0: 4 buttons and Z dir.
uhci1: <VIA 83C572 USB controller> port 0xd400-0xd41f irq 21 at device
16.1 on pci0
uhci1: [GIANT-LOCKED]
usb1: <VIA 83C572 USB controller> on uhci1
usb1: USB revision 1.0
uhub1: VIA UHCI root hub, class 9/0, rev 1.00/1.00, addr 1
uhub1: 2 ports with 2 removable, self powered
uhci2: <VIA 83C572 USB controller> port 0xd800-0xd81f irq 21 at device
16.2 on pci0
uhci2: [GIANT-LOCKED]
usb2: <VIA 83C572 USB controller> on uhci2
usb2: 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: <serial bus, USB> at device 16.3 (no driver attached)
isab0: <PCI-ISA bridge> at device 17.0 on pci0
isa0: <ISA bus> on isab0
atapci0: <VIA 8235 UDMA133 controller> port
0xdc00-0xdc0f,0x376,0x170-0x177,0x3f6,0x1f0-0x1f7 at device 17.1 on pci0
ata0: channel #0 on atapci0
ata1: channel #1 on atapci0
pcm0: <VIA VT8235> port 0xe000-0xe0ff irq 22 at device 17.5 on pci0
pcm0: [GIANT-LOCKED]
pcm0: <Avance Logic ALC650 AC97 Codec>
vr0: <VIA VT6102 Rhine II 10/100BaseTX> port 0xe400-0xe4ff mem
0xee001000-0xee0010ff irq 23 at device 18.0 on pci0
miibus0: <MII bus> on vr0
ukphy0: <Generic IEEE 802.3u media interface> on miibus0
ukphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
vr0: Ethernet address: 00:50:8d:46:5a:1f
fdc0: <floppy drive controller> port 0x3f7,0x3f2-0x3f5 irq 6 drq 2 on
acpi0
sio0 port 0x3f8-0x3ff irq 4 on acpi0
sio0: type 16550A
sio1 port 0x2f8-0x2ff irq 3 on acpi0
sio1: type 16550A
ppc0 port 0x778-0x77b,0x378-0x37f irq 7 drq 3 on acpi0
ppc0: SMC-like chipset (ECP/EPP/PS2/NIBBLE) in COMPATIBLE mode
ppc0: FIFO with 16/16/9 bytes threshold
ppbus0: <Parallel port bus> on ppc0
ppbus0: IEEE1284 device found /NIBBLE
Probing for PnP devices on ppbus0:
ppbus0: <Hewlett-Packard LaserJet 4L> HP ENHANCED PCL5,PJL
plip0: <PLIP network interface> on ppbus0
lpt0: <Printer> on ppbus0
lpt0: Interrupt-driven port
ppi0: <Parallel I/O> on ppbus0
atkbdc0: <Keyboard controller (i8042)> port 0x64,0x60 irq 1 on acpi0
atkbd0: <AT Keyboard> irq 1 on atkbdc0
kbd0 at atkbd0
atkbd0: [GIANT-LOCKED]
pmtimer0 on isa0
sc0: <System console> at flags 0x100 on isa0
sc0: VGA <16 virtual consoles, flags=0x300>
vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on
isa0
Timecounter "TSC" frequency 1467298770 Hz quality 800
Timecounters tick every 10.000 msec
acpi_cpu: throttling enabled, 2 steps (100% to 50.0%), currently 100.0%
ad0: 38146MB <IC35L060AVV207-0/V22OA66A> [77504/16/63] at ata0-master
UDMA100
ATAPI_RESET time = 10us
ATAPI_RESET time = 20us
acd0: DVDR <_NEC DVD_RW ND-2510A/2.15> at ata1-master UDMA33
acd1: CDRW <LITE-ON COMBO LTC-48161H/KH0M> at ata1-slave UDMA33
cd0 at ata1 bus 0 target 0 lun 0
cd0: <_NEC DVD_RW ND-2510A 2.15> Removable CD-ROM SCSI-0 device 
cd0: 33.000MB/s transfers
cd0: Attempt to query device size failed: NOT READY, Medium not present
cd1 at ata1 bus 0 target 1 lun 0
cd1: <LITE-ON COMBO LTC-48161H KH0M> Removable CD-ROM SCSI-0 device 
cd1: 33.000MB/s transfers
cd1: Attempt to query device size failed: NOT READY, Medium not present
Mounting root from ufs:/dev/ad0s1a

Hope this helps,
-Jay