[PATCH 03/10] mm: Convert p[te|md]_numa users to p[te|md]_protnone_numa

[Aneesh Kumar K.V]

Benjamin Herrenschmidt <benh at kernel.crashing.org> writes:

> On Fri, 2014-11-21 at 13:57 +0000, Mel Gorman wrote:
>> void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
>>                 pte_t pte)
>>  {
>> -#ifdef CONFIG_DEBUG_VM
>> -       WARN_ON(pte_val(*ptep) & _PAGE_PRESENT);
>> -#endif
>> +       /*
>> +        * When handling numa faults, we already have the pte marked
>> +        * _PAGE_PRESENT, but we can be sure that it is not in hpte.
>> +        * Hence we can use set_pte_at for them.
>> +        */
>> +       VM_WARN_ON((pte_val(*ptep) & (_PAGE_PRESENT | _PAGE_USER)) ==
>> +               (_PAGE_PRESENT | _PAGE_USER));
>> +
>
> His is that going to fare with set_pte_at() called for kernel pages ?
>

Yes, we won't capture those errors now. But is there any other debug
check i could use to capture the wrong usage of set_pte_at ?

-aneesh