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

Matthew Wilcox
2023-07-03T23:31:39Z

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?

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