Re: powerpc/e500: WARNING: at mm/hugetlb.c:4755 hugetlb_add_hstate

[Sourabh Jain <sourabhjain@linux.ibm.com>]

On 07/11/25 14:32, David Hildenbrand (Red Hat) wrote:
> On 07.11.25 09:00, Sourabh Jain wrote:
>>
>>
>> On 06/11/25 20:32, David Hildenbrand (Red Hat) wrote:
>>>>> Yes, we discussed that in [1].
>>>>>
>>>>> We'll have to set ARCH_HAS_GIGANTIC_PAGE on ppc and increase
>>>>> MAX_FOLIO_ORDER, because apparently, there might be ppc configs that
>>>>> have even larger hugetlb sizes than PUDs.
>>>>>
>>>>> @Cristophe, I was under the impression that you would send a fix. Do
>>>>> you
>>>>> want me to prepare something and send it out?
>>>>
>>>> Indeed I would have liked to better understand the implications of all
>>>> this, but I didn't have the time.
>>>
>>> Indeed, too me longer than it should to understand and make up my mind
>>> as well.
>>>
>>>>
>>>> By the way, you would describe the fix better than me so yes if you 
>>>> can
>>>> prepare and send a fix please do.
>>>
>>> I just crafted the following. I yet have to test it more, some early
>>> feedback+testing would be appreciated!
>>>
>>>  From 274928854644c49c92515f8675c090dba15a0db6 Mon Sep 17 00:00:00 2001
>>> From: "David Hildenbrand (Red Hat)" <david@kernel.org>
>>> Date: Thu, 6 Nov 2025 11:31:45 +0100
>>> Subject: [PATCH] mm: fix MAX_FOLIO_ORDER on some ppc64 configs with
>>> hugetlb
>>
>> b4 did not detect this patch, and manually copying the patch text 
>> from this
>> reply also did not apply cleanly on upstream master and linuxppc
>> master/next.
>
> I have it on a branch here:
>
> https://github.com/davidhildenbrand/linux/commit/274928854644c49c92515f8675c090dba15a0db6 
>
>
> https://github.com/davidhildenbrand/linux.git max_folio_order
>

The above patch resolves the issue reported in this thread.

Thanks for the fix David.

Thanks,
Sourabh Jain