Re: system hung up when offlining CPUs

[Christoph Hellwig]

Hi Marc,

in general the driver should know not to use the queue / irq,
as blk-mq will never schedule I/O to queues that have no online
cpus.

The real bugs seems to be that we're using affinity for a device
that only has one real queue (as the config queue should not
have affinity).  Let me dig into what's going on here with virtio.