Re: [PATCH v2] Revert "mm/pgtable: add stubs for {pmd/pub}_{set/clear}_huge"

[Michael Ellerman]

Will Deacon <will@xxxxxxxxxx> writes:
> On Wed, 21 Jul 2021 17:02:13 +1000, Michael Ellerman wrote:
>> This reverts commit c742199a014de23ee92055c2473d91fe5561ffdf.
>> 
>> c742199a014d ("mm/pgtable: add stubs for {pmd/pub}_{set/clear}_huge")
>> breaks arm64 in at least two ways for configurations where PUD or PMD
>> folding occur:
>> 
>>   1. We no longer install huge-vmap mappings and silently fall back to
>>      page-granular entries, despite being able to install block entries
>>      at what is effectively the PGD level.
>> 
>> [...]
>
> Thank you Michael! I owe you a beer next time I see you, if we don't go
> extinct before then.

No worries, thanks to Christophe for identifying the solution while on
vacation!

Beers seem a long way off, but hopefully one day :)

cheers