Re: [PATCH v1 2/4] mm/memory_hotplug: Handle unaligned start and nr_pages in online_pages_blocks()

[David Hildenbrand]

On 09.08.19 23:46, Andrew Morton wrote:
> On Fri,  9 Aug 2019 14:56:59 +0200 David Hildenbrand <david@xxxxxxxxxx> wrote:
> 
>> Take care of nr_pages not being a power of two and start not being
>> properly aligned. Essentially, what walk_system_ram_range() could provide
>> to us. get_order() will round-up in case it's not a power of two.
>>
>> This should only apply to memory blocks that contain strange memory
>> resources (especially with holes), not to ordinary DIMMs.
> 
> I'm assuming this doesn't fix any known runtime problem and that a
> -stable backport isn't needed.

Yeah, my understanding is that this would only apply when offlining and
re-onlining boot memory that contains such weird memory holes. I don't
think this is stable material.

Thanks!

> 
>> Fixes: a9cd410a3d29 ("mm/page_alloc.c: memory hotplug: free pages as higher order")
> 
> To that end, I replaced this with my new "Fixes-no-stable" in order to
> discourage -stable maintainers from overriding our decision.
> 
>> Cc: Arun KS <arunks@xxxxxxxxxxxxxx>
>> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
>> Cc: Oscar Salvador <osalvador@xxxxxxx>
>> Cc: Michal Hocko <mhocko@xxxxxxxx>
>> Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
>> Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
>> Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>


-- 

Thanks,

David / dhildenb