Le 01/09/2020 à 08:30, Aneesh Kumar K.V a écrit :

quoted

I actually wanted to add #ifdef BROKEN. That test is completely broken. 
Infact I would suggest to remove that test completely.

quoted

#ifdef will not be required here as there would be a stub definition
for hugetlb_advanced_tests() when CONFIG_PPC_BOOK3S_64 is enabled.

quoted

      spin_lock(&mm->page_table_lock);
      p4d_clear_tests(mm, p4dp);

But again, we should really try and avoid taking this path.

To be frank i am kind of frustrated with how this patch series is being 
looked at. We pushed a completely broken test to upstream and right now 
we have a code in upstream that crash when booted on ppc64. My attempt 
has been to make progress here and you definitely seems to be not in 
agreement to that.

At this point I am tempted to suggest we remove the DEBUG_VM_PGTABLE 
support on ppc64 because AFAIU it doesn't add any value.

Note that a bug has been filed at 
https://bugzilla.kernel.org/show_bug.cgi?id=209029

Christophe