Re: [PATCH v3] resource: Merge resources on a node when hot-adding memory

[Vlastimil Babka]

On 08/10/2018 08:55 AM, Rashmica Gupta wrote:
> On Fri, Aug 10, 2018 at 11:12 AM, Andrew Morton
> <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
>>
>> What is the end-user impact of this patch?
>>
> 
> Only architectures/setups that allow the user to remove and add memory of
> different sizes or different start addresses from the kernel at runtime will
> potentially encounter the resource fragmentation.
> 
> Trying to remove memory that overlaps iomem resources the first time
> gives us this warning: "Unable to release resource <%pa-%pa>".
> 
> Attempting a second time results in a kernel oops (on ppc at least).

An oops? I think that should be investigated and fixed, even if resource
merging prevents it. Do you have the details?

Thanks,
Vlastimil