Re: [PATCH 3/3] vhost: apply cpumask and cgroup to vhost workers

Tejun Heo
2010-06-01T10:56:33Z

Hello,

On 06/01/2010 12:17 PM, Michael S. Tsirkin wrote:
> Something that I wanted to figure out - what happens if the
> CPU mask limits us to a certain CPU that subsequently goes offline?

The thread gets unbound during the last steps of cpu offlining.

> Will e.g. flush block forever or until that CPU comes back?
> Also, does singlethreaded workqueue behave in the same way?

So, things will proceed as usual although the thread will lose its
affinity. Singlethread wqs don't bind their workers (and they
shouldn't! :-). MT ones explicitly manage workers according to cpu
up/down events.

Thanks.

--
tejun