Used system: Personal Workstation 500a MiataGL scsi card: QLogic ISP1020 SCSI on PCI bus 01 device 20 irq 27 I/O base 0x9000 2 harddisks of type RZ2CC-KB (C) DEC Rev: DC2B When I'm copying a lot of files, the system sometimes hangs. I don't get an oops or anything. Only thing i still can do is a hard reset. It only crashes with linux 2.4.x (i'm now using kernel-2.4.2-0.1.49 from rawhide, whole system is rawhide) The 2.2.x kernels don't have the problem. Easy reproducable: dd if=/dev/sda of=/dev/null & dd if=/dev/sdb of=/dev/null & and wait 5 minutes
the latest patch of Andrea Arcangeli which can be found at ftp://ftp.kernel.org/pub/linux/kernel/people/andrea/patches/v2.4/2.4.5pre5aa3/o_direct-7 seems to fix this problem. Wesley Daemen is the one who told me this good news. He already applied the patch and has started those dd commands to create a lot of harddisk activity and his miata doesn't crash.
2.4.4-ac17 also seems to have the fix. The fix is contained in the patch of Andrea but the original author seems to be Ivan Kokshaysky.
2.4.5 also fixes the problem.
I believe this is the tbia patch in pci_iommu.c it's a bit dirty in that as far as I remember the bits to differnetiate between tbia of 1 and 8 depending on what chipset you're running (tsunami/clipper are 8 and I think all the rest are 1. I could very well be wrong) I'm hacking in changes to the 2.4.3 kernel that will be released for 7.1 alpha Phil =--=
Let me know where i can find the rpms if you want me to test a patched version :-)
Hopefully rawhide should have kernel-2.4.3-7 That *should* work but probably not for tsunami/clipper motherboards Phil =--=