Re: 2.6.25 DMA: Out of SW-IOMMU space - Asus M2N32 AMD 8GB memory

Jari Aalto
2008-08-28T20:49:27Z

Krzysztof Halasa <khc@pm.waw.pl> writes:

> Jari Aalto <jari.aalto@cante.net> writes:
>
>> What, if after booting to 2.6.26 and without any 'iommu' boot parameters,
>> there still appears "Out of Iommu space" messages? What kind of logs
>> should I post?
>
> You shouldn't be getting "Out of SW-IOMMU space" messages when not
> using SW-IOMMU.

REF: http://article.gmane.org/gmane.linux.kernel/725293 (thread start)

I regret to report that:

- Upgraded to kernel 2.6.26-1-amd64 (Debian/unstable 2.6.26-3)

$ grep -Ei 'iommu|agp' /boot/config-2.6.26-1-amd64
CONFIG_GART_IOMMU=y
CONFIG_CALGARY_IOMMU=y
CONFIG_CALGARY_IOMMU_ENABLED_BY_DEFAULT=y
CONFIG_IOMMU_HELPER=y
CONFIG_AGP=y
CONFIG_AGP_AMD64=y
CONFIG_AGP_INTEL=m
CONFIG_AGP_SIS=m
CONFIG_AGP_VIA=m
# CONFIG_IOMMU_DEBUG is not set

- Rebooted without 'iommu' parameter. dmesg:

[ 0.000000] Kernel command line: root=UUID=cb9d814f-d885-435b-8e6d-ac17c0ac5aa1 ro quiet vga=0x317 swiotlb=32768
[ 0.004000] Checking aperture...
[ 0.004000] Node 0: aperture @ 4000000 size 32 MB
[ 0.004000] Aperture pointing to e820 RAM. Ignoring.
[ 0.004000] No AGP bridge found
[ 0.004000] Your BIOS doesn't leave a aperture memory hole
[ 0.004000] Please enable the IOMMU option in the BIOS setup
[ 0.004000] This costs you 64 MB of RAM
[ 0.004000] Mapping aperture over 65536 KB of RAM @ 4000000
...
[ 0.374935] PCI-DMA: Disabling AGP.
[ 0.374935] PCI-DMA: aperture base @ 4000000 size 65536 KB
[ 0.374935] PCI-DMA: using GART IOMMU.
[ 0.374935] PCI-DMA: Reserving 64MB of IOMMU area in the AGP aperture

- The syslog after boot reads:

Aug 28 20:18:28 jondo kernel: [972060.192696] DMA: Out of SW-IOMMU space for 24576 bytes at device 0000:00:0d.0
Aug 28 20:18:28 jondo kernel: [972060.192760] ata3.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0
Aug 28 20:18:28 jondo kernel: [972060.196705] ata3.00: cmd ca/00:60:c1:91:5f/00:00:00:00:00/e8 tag 0 dma 49152 out
Aug 28 20:18:28 jondo kernel: [972060.196707] res 50/00:00:bf:cf:b5/00:00:71:00:00/ea Emask 0x40 (internal error)
Aug 28 20:18:28 jondo kernel: [972060.200700] ata3.00: status: { DRDY }
Aug 28 20:18:28 jondo kernel: [972060.231128] ata3.00: configured for UDMA/133
Aug 28 20:18:28 jondo kernel: [972060.231137] ata3: EH complete
Aug 28 20:18:28 jondo kernel: [972060.231148] DMA: Out of SW-IOMMU space for 24576 bytes at device 0000:00:0d.0
Aug 28 20:18:28 jondo kernel: [972060.233247] ata3.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0
Aug 28 20:18:28 jondo kernel: [972060.237246] ata3.00: cmd
ca/00:60:c1:91:5f/00:00:00:00:00/e8 tag 0 dma 49152 out

>> I'm a bit nervous due to past experience of complete hardd disk
>> corruption. But if that was problem with the old kernel and more later
>> versions are safer in this repect, I could once more.
>
> I'm not sure if the newer versions are safer. It may be a hardware/BIOS
> problem and it may happen again. Make sure you have a usable backup
> first.

If there is anything I can do, please let me know. This must be a kernel
issue somewhere.

My BE-2400 processor still continues to freeze after few days.

Jari