UltraSPARC T2 and UltraSPARC T2 Plus Based Systems: Domain Might Panic When Adding New CPUs

Bug ID 6837313: Under rare circumstances on UltraSPARC T2 and UltraSPARC T2 Plus based systems, adding new CPUs to a domain might cause that domain to panic. This panic is more likely to occur when CPUs are added after PCI buses have been added or removed.

Impact: The domain panics with a stack trace that might contain references to the n2rng driver.

Workaround: This problem is triggered when the n2rng driver initializes structures for storing statistics. The problem can be prevented by disabling the generation of statistics for the n2rng driver, as follows:

• Edit the /platform/sun4v/kernel/drv/n2rng.conf file to add the following line:

  nostats=1;

• Update the n2rng driver by running the following command:

  # update_drv n2rng