Le 14/05/2021 à 23:42, Andrew Morton a écrit :

On Fri, 14 May 2021 11:08:53 +0000 (UTC) Christophe Leroy [off-list ref] wrote:

quoted

When PUD and/or PMD are folded, those functions are useless
and we now have a stub in linux/pgtable.h

OK, help me out here please.  What patch does this fix?

Both this one and the x86 one from the day before fix 1cff41494b15cd82c1ec418bb5c ("mm/pgtable: add 
stubs for {pmd/pub}_{set/clear}_huge")

I think both the x86 fix and the arm64 fix should be squashed into that patch at the end.

I checked, the only other architecture involving pud_set_huge() and friends is powerpc, and powerpc 
doesn't have this problem as it only defined those for book3s/64 platforms which have 4 level page 
tables by definition.

Thanks
Christophe