Re: [PATCH 3/4] mm/memory: convert do_shared_fault() to folios

Sidhartha Kumar
2023-07-04T02:19:19Z

On 7/3/23 4:31 PM, Matthew Wilcox wrote:
> On Sun, Jul 02, 2023 at 10:58:49PM -0700, Sidhartha Kumar wrote:
>> Saves three implicit calls to compound_head().
>>
>> Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
>> ---
>> mm/memory.c | 9 +++++----
>> 1 file changed, 5 insertions(+), 4 deletions(-)
>>
>> diff --git a/mm/memory.c b/mm/memory.c
>> index 93480e846ace6..33bf13431974c 100644
>> --- a/mm/memory.c
>> +++ b/mm/memory.c
>> @@ -4594,6 +4594,7 @@ static vm_fault_t do_shared_fault(struct vm_fault *vmf)
>> {
>> struct vm_area_struct *vma = vmf->vma;
>> vm_fault_t ret, tmp;
>> + struct folio *folio = page_folio(vmf->page);
>
> You can't call page_folio() until after __do_fault(). Did you test this
> series?

I thought it would be straightforward enough without testing but I
didn't realize the initialization in __do_fault(). I will test and
incorporate the other suggestions for a v2.

Thanks
>
>> ret = __do_fault(vmf);
>> if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE | VM_FAULT_RETRY)))