Comment 26 for bug 96692

Happens also for with Macbook2,1 and latest Karmic upgraded to 20091016 (2.6.31-14)

Computer is very very very slow when doing I/O (basically bloated even when copying some files)

uname -a:
Linux xxxxx 2.6.31-14-generic #47-Ubuntu SMP Thu Oct 15 02:08:08 UTC 2009 i686 GNU/Linux

dmesg:
[ 0.869569] ata_piix 0000:00:1f.1: version 2.13
[ 0.869613] ata_piix 0000:00:1f.1: power state changed by ACPI to D0
[ 0.869621] alloc irq_desc for 18 on node -1
[ 0.869624] alloc kstat_irqs on node -1
[ 0.869629] ata_piix 0000:00:1f.1: PCI INT A -> GSI 18 (level, low) -> IRQ 18
[ 0.869672] ata_piix 0000:00:1f.1: setting latency timer to 64
[ 0.869787] scsi0 : ata_piix
[ 0.869958] scsi1 : ata_piix
[ 0.870573] ata1: PATA max UDMA/100 cmd 0x1f0 ctl 0x3f6 bmdma 0x20b0 irq 14
[ 0.870577] ata2: PATA max UDMA/100 cmd 0x170 ctl 0x376 bmdma 0x20b8 irq 15
[ 0.870600] alloc irq_desc for 19 on node -1
[ 0.870602] alloc kstat_irqs on node -1
[ 0.870607] ata_piix 0000:00:1f.2: PCI INT B -> GSI 19 (level, low) -> IRQ 19
[ 0.870613] ata_piix 0000:00:1f.2: MAP [ P0 P2 -- -- ]
[ 0.998987] ACPI: Battery Slot [BAT0] (battery present)
[ 1.035298] ata_piix 0000:00:1f.2: setting latency timer to 64
[ 1.035430] scsi2 : ata_piix
[ 1.035535] scsi3 : ata_piix
[ 1.036519] ata3: SATA max UDMA/133 cmd 0x20c8 ctl 0x20ec bmdma 0x20a0 irq 19
[ 1.036522] ata4: SATA max UDMA/133 cmd 0x20c0 ctl 0x20e8 bmdma 0x20a8 irq 19

lspci -vvnn:
00:1f.1 IDE interface [0101]: Intel Corporation 82801G (ICH7 Family) IDE Controller [8086:27df] (rev 02) (prog-if 8a [Master SecP PriP])
 Subsystem: Intel Corporation Device [8086:7270]
 Control: I/O+ Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
 Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
 Latency: 0
 Interrupt: pin A routed to IRQ 18
 Region 0: I/O ports at 01f0 [size=8]
 Region 1: I/O ports at 03f4 [size=1]
 Region 2: I/O ports at 0170 [size=8]
 Region 3: I/O ports at 0374 [size=1]
 Region 4: I/O ports at 20b0 [size=16]
 Kernel driver in use: ata_piix

00:1f.2 IDE interface [0101]: Intel Corporation 82801GBM/GHM (ICH7 Family) SATA IDE Controller [8086:27c4] (rev 02) (prog-if 8f [Master SecP SecO PriP PriO])
 Subsystem: Intel Corporation Device [8086:7270]
 Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
 Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
 Latency: 0
 Interrupt: pin B routed to IRQ 19
 Region 0: I/O ports at 20c8 [size=8]
 Region 1: I/O ports at 20ec [size=4]
 Region 2: I/O ports at 20c0 [size=8]
 Region 3: I/O ports at 20e8 [size=4]
 Region 4: I/O ports at 20a0 [size=16]
 Region 5: Memory at 90445000 (32-bit, non-prefetchable) [size=1K]
 Capabilities: <access denied>
 Kernel driver in use: ata_piix