Re: [PATCH v6] mm/hugetlb: ignore hugepage kernel args if hugepages are unsupported

Sourabh Jain
2025-12-22T05:58:59Z

On 22/12/25 08:42, Ritesh Harjani (IBM) wrote:
> "David Hildenbrand (Red Hat)" <david@kernel.org> writes:
>
>>> Coming back to the fixes tag. I did mention a bit of a history [2] of
>>> whatever I could find while reviewing this patch. I am not sure whether
>>> you have looked into the links shared in that email or not. Here [2]:
>>>
>>> [2]: https://lore.kernel.org/linuxppc-dev/875xa3ksz9.ritesh.list@gmail.com/
>>>
>>> Where I am coming from is.. The current patch is acutally a partial
>>> revert of the patch mentioned in the fixes tag. That means if this patch
>>> gets applied to the older stable kernels, it would end up bringing the
>>> same problem back, which the "Fixes" tagged patch is fixing in the 1st
>>> place, isnt' it? See this discussion [3]...
>>>
>>> [3]: https://lore.kernel.org/all/b1f04f9f-fa46-c2a0-7693-4a0679d2a1ee@oracle.com/T/#m0eee87b458d93559426b8b0e78dc6ebcd26ad3ae
>>>
>>> ... So, IMO - the right fixes tag, if we have to add, it should be the
>>> patch which moved the hpage_shift initialization to happen early i.e. in
>>> mmu_early_init_devtree. That would be this patch [4]:
>>>
>>> [4]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2354ad252b66695be02f4acd18e37bf6264f0464
>>>
>>> Now, it's not really that the patch [4] had any issue as such. But it
>>> seems like, that the current fix can only be applied after patch [4] is
>>> taken.
>>>
>>> Do we agree?
>> I think we should document all that in the cover letter, an describe
>> that this partial revert is only possible after [4],
> Yes, I agree. Let's add the above details in the commit msg.
>
>> and that that must
>> be considered when attempting any kind of stable backports.
> Sure. I would prefer if we change the Fixes tag to the one which I
> pointed in above [4] (with explaination in the commit msg). However I am
> still ok if we would like to retain the existing fixes tag and show [4]
> as a dependency.

I think we should keep the current Fixes tag with an explanation for
dependency
on [1] in the commit message.

Would anyone have a different view?

[1]
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=2354ad252b66695be02f4acd18e37bf6264f0464

- Sourabh Jain