Re: [2.6.15] frequent "BUG: soft lockup detected on CPU#0" in IDEsubsystem

From: Folkert van Heusden
Date: Wed Feb 08 2006 - 03:48:18 EST

> >kernel: 2.6.15
> >system: 3.2GHz P4 hyperthreading, 1xIDE, 2GB ram
> >it seems to happen (altough I'm really not sure!) when the system is
> >under heavily load: > 8.0, while running sa-learn (the spamassassin
> >bayes training tool)
> Lots of PIO transfers.. Is DMA not getting enabled on your drives?

According to this, DMA is enabled:

0 root@muur:/usr/src/linux-2.6.15/Documentation$ hdparm -i /dev/hda


Model=QUANTUM FIREBALLP AS20.5, FwRev=A2R.0600, SerialNo=692124031358
Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs }
RawCHS=16383/16/63, TrkSize=32256, SectSize=21298, ECCbytes=4
BuffType=DualPortCache, BuffSize=1902kB, MaxMultSect=16, MultSect=16
CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=40132503
IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes: pio0 pio1 pio2 pio3 pio4
DMA modes: mdma0 mdma1 mdma2
UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5
AdvancedPM=no WriteCache=enabled
Drive conforms to: ATA/ATAPI-5 T13 1321D revision 1:

* signifies the current active mode

Also, I run this at startup:
/usr/sbin/hdparm -c 3 -d 1 -X 69 -u 1 /dev/hda

Oh and at bootup it says it uses DMA for that drive:
[ 0.431334] Uniform Multi-Platform E-IDE driver Revision: 7.00alpha2
[ 0.431375] ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
[ 0.431440] ICH5: IDE controller at PCI slot 0000:00:1f.1
[ 0.431482] PCI: Enabling device 0000:00:1f.1 (0005 -> 0007)
[ 0.431524] ACPI: PCI Interrupt 0000:00:1f.1[A] -> GSI 18 (level, low) -> IRQ 17
[ 0.431604] ICH5: chipset revision 2
[ 0.431641] ICH5: not 100% native mode: will probe irqs later
[ 0.431687] ide0: BM-DMA at 0xfc00-0xfc07, BIOS settings: hda:DMA, hdb:pio
[ 0.431799] ide1: BM-DMA at 0xfc08-0xfc0f, BIOS settings: hdc:DMA, hdd:pio
[ 0.431909] Probing IDE interface ide0...
[ 0.749711] hda: QUANTUM FIREBALLP AS20.5, ATA DISK drive
[ 1.479391] ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
[ 1.479514] Probing IDE interface ide1...
[ 2.268919] hdc: CREATIVEDVD6630E, ATAPI CD/DVD-ROM drive
[ 2.638776] ide1 at 0x170-0x177,0x376 on irq 15
[ 2.638996] hda: max request size: 128KiB
[ 2.640382] hda: 40132503 sectors (20547 MB) w/1902KiB Cache, CHS=39813/16/63, UDMA(100)
[ 2.640548] hda: cache flushes not supported
[ 2.640625] hda: hda1 hda2 hda3
[ 2.645987] usbmon: debugfs is not available

A strange thing is, though, that I only get 5MB/s with hdparm -t.

Folkert van Heusden

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