Re: [7/8,v3] NUMA Hotplug Emulator: extend memory probe interface to support NUMA

David Rientjes
2010-11-18T21:31:54Z

On Thu, 18 Nov 2010, Shaohui Zheng wrote:

> > Then, export the amount of memory that is actually physically present in
> > the e820 but was truncated by mem= and allow users to hot-add the memory
> > via the probe interface. Add a writeable 'node' file to offlined memory
> > section directories and allow it to be changed prior to online.
>
> for memory offlining, it is a known diffcult thing, and it is not supported
> well in current kernel, so I do not suggest to provide the offline interface
> in the emulator, it just take more pains. We can consider to add it when
> the memory offlining works well.
>

You're referring to the inability to remove memory sections for
CONFIG_SPARSEMEM_VMEMMAP? You should still able to test the offlining
with other memory models of emulated nodes by using the generic support
already implemented for CONFIG_MEMORY_HOTREMOVE; the short answer is that
it probably shouldn't matter at all since we already support node
hot-remove and the fact that they are emulated nodes isn't really of
interest.