Re: [PATCH v7 0/5] Make cpuid <-> nodeid mapping persistent

[Tejun Heo]

On Mon, May 23, 2016 at 03:02:14PM +0800, Zhu Guihua wrote:
> We tried to do that. You can see our patch at
> http://www.gossamer-threads.com/lists/linux/kernel/2116748
> 
> But maintainer thought, we should establish persistent cpuid<->nodeid
> relationship,
> there is no need to change the map.
> 
> Cc TJ,
> Could we return to workqueue to fix this?

Workqueue is just one of symptoms.  We have the same problem for
memory allocation paths.  It's either keeping cpu <-> node mapping
persistent or hunting down every case which may be affected and build
likely costly synchronization construct around it.  It's not like we
have a lot of archs which support CPU hotplug and NUMA.

Thanks.

-- 
tejun