Re: mm: deadlock between get_online_cpus/pcpu_alloc

[Christoph Lameter]

On Tue, 7 Feb 2017, Thomas Gleixner wrote:

> > Yep. Hotplug events are pretty significant. Using stop_machine_XXXX() etc
> > would be advisable and that would avoid the taking of locks and get rid of all the
> > ocmplexity, reduce the code size and make the overall system much more
> > reliable.
>
> Huch? stop_machine() is horrible and heavy weight. Don't go there, there
> must be simpler solutions than that.

Inserting or removing hardware is a heavy process. This would help quite a
bit with these issues for loops over active cpus.