James Bottomley wrote:
On Sun, 2008-03-09 at 21:29 +0900, FUJITA Tomonori wrote:
On Sun, 09 Mar 2008 14:23:13 +0300
Michael Tokarev <mjt@xxxxxxxxxx> wrote:
Just got quite.. bad situation on a production server
here. The machine locked up hard several times in a
row (required hard reboot). So I finally enabled watchdog
subsystem which helped.
Now I see the following (over netconsole):
DMA: Out of SW-IOMMU space for 65536 bytes at device 0000:08:07.0
------------[ cut here ]------------
kernel BUG at drivers/scsi/aic7xxx/aic79xx_osm.c:1490!
Seems that you was out of swiommu space (and aic79xx can't handle it
though it should). This happened because:
a) you produced more I/Os than swiommu can handle.
b) swiommu space leaks due to bugs.
If you hit this problem due to a), the following boot option might
help:
swiotlb=65536
Running with this parameter now - no lockups so far.
Actually, it's worse than this. The aic79xx is a fully 64 bit capable
PCI card, it shouldn't be using the iommu at all. However, it has three
DMA modes: 64 bit, 39 bit and 32 bit; with a corresponding resource
cost increasing with the number of bits. It employs special APIs to
size the masks according to the memory, in aic79xx_osm_pci.c:
[]
Could you firstly tell me how much memory you have, and secondly
instrument this code with the patch below to see if we can work out what
it's doing?
The memory map is below (6Gb total). The patch - kernel is being compiled
right now.
Linux version 2.6.24-x86-64 (mjt@xxxxxxxxxxxxxxxxx) (gcc version 4.2.3 20071123 (prerelease) (Debian 4.2.2-4)) #2.6.24.2 SMP Mon Feb 18 16:04:41 MSK 2008
Command line: auto BOOT_IMAGE=linux-test ro root=100 swiotlb=65536 panic=30 elevator=deadline
BIOS-provided physical RAM map:
BIOS-e820: 0000000000000000 - 000000000009dc00 (usable)
BIOS-e820: 000000000009dc00 - 00000000000a0000 (reserved)
BIOS-e820: 00000000000e0000 - 0000000000100000 (reserved)
BIOS-e820: 0000000000100000 - 00000000cfffca00 (usable)
BIOS-e820: 00000000cfffca00 - 00000000d0000000 (ACPI data)
BIOS-e820: 00000000e0000000 - 00000000f0000000 (reserved)
BIOS-e820: 00000000fec00000 - 0000000100000000 (reserved)
BIOS-e820: 0000000100000000 - 00000001b0000000 (usable)
/mjt
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