"Kirill A. Shutemov" <kir...@shutemov.name> writes:
> On Mon, Nov 07, 2016 at 02:04:41PM +0530, Aneesh Kumar K.V wrote:
>> @@ -2953,6 +2966,13 @@ static int do_set_pmd(struct fault_env *fe, struct
>> page *page)
>> ret = VM_FAULT_FALLBACK;
>> page = compound_head(page);
>>
>> + /*
>> + * Archs like ppc64 need additonal space to store information
>> + * related to pte entry. Use the preallocated table for that.
>> + */
>> + if (arch_needs_pgtable_deposit() && !fe->prealloc_pte)
>> + fe->prealloc_pte = pte_alloc_one(vma->vm_mm, fe->address);
>> +
>
> -ENOMEM handling?
How about
if (arch_needs_pgtable_deposit() && !fe->prealloc_pte) {
fe->prealloc_pte = pte_alloc_one(vma->vm_mm, fe->address);
if (!fe->prealloc_pte)
return VM_FAULT_OOM;
}
>
> I think we should do this way before this point. Maybe in do_fault() or
> something.
doing this in do_set_pmd keeps this closer to where we set the pmd. Any
reason you thing we should move it higher up the stack. We already do
pte_alloc() at the same level for a non transhuge case in
alloc_set_pte().
-aneesh
