Re: [PATCH v2] mm/memory-failure: Support disabling soft offline for HugeTLB pages

David Hildenbrand
2025-09-17T07:03:03Z

>> +
>> + 0 - Enable soft offline
>> + 1 - Disable soft offline for HugeTLB pages
>> +
>> +Supported values::
>> +
>> + 0 - Soft offline is disabled
>> + 1 - Soft offline is enabled
>> + 3 - Soft offline is enabled (disabled for HugeTLB pages)
>
> This looks very adhoc even though existing behavior is preserved.
>
> - Are HugeTLB pages the only page types to be considered ?
> - How the remaining bits here are going to be used later ?
>

What I proposed (that could be better documented here) is that all other
bits except the first one will be a disable mask when bit 0 is set.

2 - ... but yet disabled for hugetlb
4 - ... but yet disabled for $WHATEVER
8 - ... but yet disabled for $WHATEVERELSE

> Also without a bit-wise usage roadmap, is not changing a procfs
> interface (ABI) bit problematic ?

For now we failed setting it to values that are neither 0 or 1, IIUC
set_enable_soft_offline() correctly?

So there should not be any problem, or which scenario do you have in mind?

--
Cheers

David / dhildenb