[PATCH v6 4/7] mm/memblock: add a reserved-region flag for poisoned frames

[David Hildenbrand (Arm)]

On 10/22/26 18:33, Mike Rapoport wrote:
> Hi Breno,
> 
> On Fri, Oct 16, 2026 at 05:15:44AM -0700, Breno Leitao wrote:
>> memblock allocates from and frees to buddy whatever is not reserved, and
>> knows nothing about frames an earlier kernel found hardware-poisoned.
>> Such a frame can back the memmap, a page table or a percpu area before
>> any hwpoison code runs, and otherwise reaches the buddy allocator like
>> any other free frame.
>>
>> Add MEMBLOCK_RSRV_HWPOISON for a reserved range holding those frames.
> 
> How much this would fragment memblock.reserved?
> 
> memblock is not very scalable, to say the least, and each new flag
> increases the size of memblock arrays which obviously hurts performance.

I assume that if you have too many regions there, you have different problems
than scalability problems.

We should cut out larger chunks, and if they are all over your address space you
should scrap that machine.

-- 
Cheers,

David