Hi, I have a board with an AMCC440 processor, running RAID5 using the async-tx interface. In general, it works well, but I have found a test case that consistently causes a hard lockup of the entire system. What makes this case odd is that I have only been able to generate it when accessing disks that are on two separate HBAs - in my case mpt-fusion based SAS HBAs. Once two HBAs are in use, the bug is trivial to repeat. I simply create a RAID5 using disks from each HBA, wait for it to resync, and then run "dd if=/dev/zero of=/dev/md0 bs=512 count=100000". By disabling CONFIG_DMA_ENGINE in my kernel config, the hang goes away, but then so does my performance. Any pointers on how to debug this? It feels like a race condition of some description, but any serial port printing I enable causes the problem to go away, and I can't print silently to /var/log/messages as the system hangs before it can flush. Regards, Dale - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
