On 4/5/24 3:23 PM, David Hildenbrand wrote:
> On 25.03.24 13:48, alexs@xxxxxxxxxx wrote:
>> From: "Alex Shi (tencent)" <alexs@xxxxxxxxxx>
>>
>> Compound page is checked and skipped before write_protect_page() called,
>> use folio to save a few compound_head checking.
>>
>> Signed-off-by: Alex Shi (tencent) <alexs@xxxxxxxxxx>
>> Cc: Izik Eidus <izik.eidus@xxxxxxxxxxxxxxxxxx>
>> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
>> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
>> Cc: Hugh Dickins <hughd@xxxxxxxxxx>
>> Cc: Chris Wright <chrisw@xxxxxxxxxxxx>
>> ---
>> mm/ksm.c | 22 +++++++++++-----------
>> 1 file changed, 11 insertions(+), 11 deletions(-)
>>
>> diff --git a/mm/ksm.c b/mm/ksm.c
>> index 95a487a21eed..5d1f62e7462a 100644
>> --- a/mm/ksm.c
>> +++ b/mm/ksm.c
>> @@ -1289,22 +1289,22 @@ static u32 calc_checksum(struct page *page)
>> return checksum;
>> }
>> -static int write_protect_page(struct vm_area_struct *vma, struct page *page,
>> +static int write_protect_page(struct vm_area_struct *vma, struct folio *folio,
>> pte_t *orig_pte)
>> {
>> struct mm_struct *mm = vma->vm_mm;
>> - DEFINE_PAGE_VMA_WALK(pvmw, page, vma, 0, 0);
>> + DEFINE_FOLIO_VMA_WALK(pvmw, folio, vma, 0, 0);
>> int swapped;
>> int err = -EFAULT;
>> struct mmu_notifier_range range;
>> bool anon_exclusive;
>> pte_t entry;
>> - pvmw.address = page_address_in_vma(page, vma);
>> + pvmw.address = page_address_in_vma(&folio->page, vma);
>> if (pvmw.address == -EFAULT)
>> goto out;
>> - BUG_ON(PageTransCompound(page));
>> + VM_BUG_ON(folio_test_large(folio));
>
> I suggest
>
> if (WARN_ON_ONCE(folio_test_large(folio)))
> return err;
>
> before the page_address_in_vma() call.
>
Thanks for the suggestion, will take it.
>
> Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
>
