On 02/25/2010 06:47 AM, Will Storey wrote:
Hi,

I was attempting to test temperatures under load by running "cat
/dev/urandom>  file" and I thought my system had crashed. Instantly when
this command begins the system becomes very unresponsive. All input over ssh
and keyboard attached to the machine has seemingly varying, but significant,
amounts of lag.

I'm not sure what would be causing this behaviour or how to properly
diagnose it.
The system in question is using the Intel Atom D510MO motherboard (
http://www.intel.com/products/desktop/motherboards/D510MO/D510MO-overview.htm
).

I'm not sure how relevant this is, but the top output seems to indicate
something:

load averages:  1.73,  0.97,  0.46
03:18:14
33 processes:  30 idle, 3 on processor
CPU0 states:  0.0% user,  0.0% nice,  0.4% system, 99.6% interrupt,  0.0%
idle
CPU1 states:  0.0% user,  0.0% nice,  6.3% system, 53.6% interrupt, 40.1%
idle
CPU2 states:  0.0% user,  0.0% nice,  100% system,  0.0% interrupt,  0.0%
idle
CPU3 states:  0.0% user,  0.0% nice,  3.7% system, 50.5% interrupt, 45.8%
idle
Memory: Real: 10M/137M act/tot  Free: 845M  Swap: 0K/2051M used/tot

   PID USERNAME PRI NICE  SIZE   RES STATE     WAIT      TIME    CPU COMMAND
16216 root      -5    0  184K  148K sleep/2   getblk   11:18 1129.88% cat
15668 _ntp      56    0  708K  812K onproc/0  -         0:42 77.64% ntpd
  2808 root       2    0  624K  724K sleep/3   poll      0:17 60.40% ntpd
  6584 root      32    0  808K 1392K onproc/1  -         0:08  9.23% top
16545 root      32    0  968K 1420K onproc/3  -         0:04  8.15% sendmail
23931 will       2    0 3340K 1812K sleep/1   select    0:01  2.54% sshd
   197 _syslogd   2    0  488K  644K sleep/1   poll      0:00  1.76% syslogd
  2449 _pflogd    4    0  540K  292K sleep/3   bpf       0:01  1.71% pflogd
17554 will       2    0 3200K 1804K idle      select    0:03  0.83% sshd

This is after leaving the process running for a few minutes. top updates
maybe once every minute while this goes on and the % cpu time slowly
increases

I'm aware this is a newish piece of equipment and may not be fully supported
yet so I'm not sure if that is the reason or there is some bug here. Or that
this is anything that should be too worried about.

I initially found this behaviour on 4.6-release but then tried the Feb 23?
(or which is on ftp as of a couple hours ago) snapshot. Same behaviour on
both. Both were i386. I haven't yet tried amd64.

Also, I tried a different test running infinite loops to max out all the
CPUs and the system seemed to behave fine.

Oh, I just tried the SP kernel while writing this and the problem only seems
to occur when running the MP kernel.

Sorry for the noise if I'm missing something.

Here's the dmesg:

OpenBSD 4.7-beta (GENERIC.MP) #423: Tue Feb 23 12:24:22 MST 2010
     dera...@i386.openbsd.org:/usr/src/sys/arch/i386/compile/GENERIC.MP
RTC BIOS diagnostic error 80<clock_battery>
cpu0: Intel(R) Atom(TM) CPU D510 @ 1.66GHz ("GenuineIntel" 686-class) 1.67
GHz
cpu0:
FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,SBF,SSE3,MWAIT,DS-CPL,TM2,CX16,xTPR
real mem  = 1055203328 (1006MB)
avail mem = 1013702656 (966MB)
RTC BIOS diagnostic error 80<clock_battery>
mainbus0 at root
bios0 at mainbus0: AT/286+ BIOS, date 11/17/09, SMBIOS rev. 2.5 @ 0xe4410
(25 entries)
bios0: vendor Intel Corp. version "MOPNV10J.86A.0154.2009.1117.1624" date
11/17/2009
bios0: Intel Corporation D510MO
acpi0 at bios0: rev 2
acpi0: tables DSDT FACP APIC MCFG HPET SSDT
acpi0: wakeup devices SLPB(S4) PS2M(S4) PS2K(S4) UAR1(S4) UAR2(S4) P32_(S4)
ILAN(S4) PEX0(S4) PEX1(S4) PEX2(S4) PEX3(S4) UHC1(S3) UHC2(S3) UHC3(S3)
UHC4(S3) EHCI(S3) AZAL(S4)
acpitimer0 at acpi0: 3579545 Hz, 24 bits
acpimadt0 at acpi0 addr 0xfee00000: PC-AT compat
cpu0 at mainbus0: apid 0 (boot processor)
cpu0: apic clock running at 166MHz
cpu1 at mainbus0: apid 1 (application processor)
cpu1: Intel(R) Atom(TM) CPU D510 @ 1.66GHz ("GenuineIntel" 686-class) 1.67
GHz
cpu1:
FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,SBF,SSE3,MWAIT,DS-CPL,TM2,CX16,xTPR
cpu2 at mainbus0: apid 2 (application processor)
cpu2: Intel(R) Atom(TM) CPU D510 @ 1.66GHz ("GenuineIntel" 686-class) 1.67
GHz
cpu2:
FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,SBF,SSE3,MWAIT,DS-CPL,TM2,CX16,xTPR
cpu3 at mainbus0: apid 3 (application processor)
cpu3: Intel(R) Atom(TM) CPU D510 @ 1.66GHz ("GenuineIntel" 686-class) 1.67
GHz
cpu3:
FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CFLUSH,DS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,SBF,SSE3,MWAIT,DS-CPL,TM2,CX16,xTPR
ioapic0 at mainbus0: apid 8 pa 0xfec00000, version 20, 24 pins
ioapic0: misconfigured as apic 0, remapped to apid 8
acpihpet0 at acpi0: 14318179 Hz
acpiprt0 at acpi0: bus 5 (P32_)
acpiprt1 at acpi0: bus 0 (PCI0)
acpiprt2 at acpi0: bus 1 (PEX0)
acpiprt3 at acpi0: bus 2 (PEX1)
acpiprt4 at acpi0: bus 3 (PEX2)
acpiprt5 at acpi0: bus 4 (PEX3)
acpicpu0 at acpi0: C1, PSS
acpicpu1 at acpi0: C1, PSS
acpicpu2 at acpi0: C1, PSS
acpicpu3 at acpi0: C1, PSS
acpibtn0 at acpi0: SLPB
bios0: ROM list: 0xc0000/0xda00! 0xce000/0x1000
pci0 at mainbus0 bus 0: configuration mode 1 (bios)
pchb0 at pci0 dev 0 function 0 "Intel Pineview DMI Bridge" rev 0x02
vga1 at pci0 dev 2 function 0 "Intel Pineview Integrated Graphics
Controller" rev 0x02
wsdisplay0 at vga1 mux 1: console (80x25, vt100 emulation)
wsdisplay0: screen 1-5 added (80x25, vt100 emulation)
intagp at vga1 not configured
ppb0 at pci0 dev 28 function 0 "Intel 82801GB PCIE" rev 0x01: apic 8 int 17
(irq 255)
pci1 at ppb0 bus 1
re0 at pci1 dev 0 function 0 "Realtek 8168" rev 0x03: RTL8168D/8111D
(0x2800), apic 8 int 16 (irq 11), address 00:27:0e:09:78:51
rgephy0 at re0 phy 7: RTL8169S/8110S PHY, rev. 2
ppb1 at pci0 dev 28 function 1 "Intel 82801GB PCIE" rev 0x01: apic 8 int 16
(irq 255)
pci2 at ppb1 bus 2
ppb2 at pci0 dev 28 function 2 "Intel 82801GB PCIE" rev 0x01: apic 8 int 18
(irq 255)
pci3 at ppb2 bus 3
ppb3 at pci0 dev 28 function 3 "Intel 82801GB PCIE" rev 0x01: apic 8 int 19
(irq 255)
pci4 at ppb3 bus 4
uhci0 at pci0 dev 29 function 0 "Intel 82801GB USB" rev 0x01: apic 8 int 23
(irq 9)
uhci1 at pci0 dev 29 function 1 "Intel 82801GB USB" rev 0x01: apic 8 int 19
(irq 10)
uhci2 at pci0 dev 29 function 2 "Intel 82801GB USB" rev 0x01: apic 8 int 18
(irq 11)
uhci3 at pci0 dev 29 function 3 "Intel 82801GB USB" rev 0x01: apic 8 int 16
(irq 11)
ehci0 at pci0 dev 29 function 7 "Intel 82801GB USB" rev 0x01: apic 8 int 23
(irq 9)
usb0 at ehci0: USB revision 2.0
uhub0 at usb0 "Intel EHCI root hub" rev 2.00/1.00 addr 1
ppb4 at pci0 dev 30 function 0 "Intel 82801BAM Hub-to-PCI" rev 0xe1
pci5 at ppb4 bus 5
fxp0 at pci5 dev 0 function 0 "Intel 8255x" rev 0x08, i82559: apic 8 int 21
(irq 9), address 00:90:27:87:40:3b
inphy0 at fxp0 phy 1: i82555 10/100 PHY, rev. 4
pcib0 at pci0 dev 31 function 0 "Intel Tigerpoint LPC Controller" rev 0x01
pciide0 at pci0 dev 31 function 2 "Intel 82801GB SATA" rev 0x01: DMA,
channel 0 configured to native-PCI, channel 1 configured to native-PCI
pciide0: using apic 8 int 19 (irq 10) for native-PCI interrupt
wd0 at pciide0 channel 1 drive 0:<SAMSUNG HD502HJ>
wd0: 16-sector PIO, LBA48, 476940MB, 976773168 sectors
wd0(pciide0:1:0): using PIO mode 4, Ultra-DMA mode 6
ichiic0 at pci0 dev 31 function 3 "Intel 82801GB SMBus" rev 0x01: apic 8 int
19 (irq 10)
iic0 at ichiic0
spdmem0 at iic0 addr 0x51: 1GB DDR2 SDRAM non-parity PC2-6400CL5
usb1 at uhci0: USB revision 1.0
uhub1 at usb1 "Intel UHCI root hub" rev 1.00/1.00 addr 1
usb2 at uhci1: USB revision 1.0
uhub2 at usb2 "Intel UHCI root hub" rev 1.00/1.00 addr 1
usb3 at uhci2: USB revision 1.0
uhub3 at usb3 "Intel UHCI root hub" rev 1.00/1.00 addr 1
usb4 at uhci3: USB revision 1.0
uhub4 at usb4 "Intel UHCI root hub" rev 1.00/1.00 addr 1
isa0 at pcib0
isadma0 at isa0
pckbc0 at isa0 port 0x60/5
pckbd0 at pckbc0 (kbd slot)
pckbc0: using irq 1 for kbd slot
wskbd0 at pckbd0: console keyboard, using wsdisplay0
pcppi0 at isa0 port 0x61
midi0 at pcppi0:<PC speaker>
spkr0 at pcppi0
wbsio0 at isa0 port 0x4e/2: W83627THF rev 0x84
lm1 at wbsio0 port 0x290/8: W83627THF
npx0 at isa0 port 0xf0/16: reported by CPUID; using exception 16
mtrr: Pentium Pro MTRR support
vscsi0 at root
scsibus0 at vscsi0: 256 targets
softraid0 at root
root on wd0a swap on wd0b dump on wd0b

Thanks,

cpu and disk io...

run it with 'nice -n 20 cat /dev/urandom > file'
to fix the cpu problem, as far as the disk io problem enable a different scheduler, such as READPRIO in the kernel which will give reading priority and will not make things like 'uname' take 3 seconds to complete when a large tarbal is being extracted (especially with log/softdep options in fstab, which are very useful, yet they cram stuff in the write queue and the read queue of other commands barely get a chance)

so yea, creating random data takes cpu cycles, schedule it correctly, using disk takes io, schedule it correctly, and not so much on subject but using the network takes bandwidth, so schedule that correctly to.

once done, your system/network can be at max production yet still be completely responsive for what you choose it to be completely responsive for (as if nothing was going on).

Noah McNallie
n0ah

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