Re: [PATCH 15/16] debug_vm_pgtable/savedwrite: Use savedwrite test with protnone ptes

[Anshuman Khandual]

On 08/12/2020 12:03 PM, Aneesh Kumar K.V wrote:
> Saved write support was added to track the write bit of a pte after marking 
> the
> pte protnone. This was done so that AUTONUMA can convert a write pte to 
> protnone
> and still track the old write bit. When converting it back we set the pte 
> write
> bit correctly thereby avoiding a write fault again.
> 
> Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com>
> ---
>  mm/debug_vm_pgtable.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/mm/debug_vm_pgtable.c b/mm/debug_vm_pgtable.c
> index 3e112d0ba1b2..eea62d5e503b 100644
> --- a/mm/debug_vm_pgtable.c
> +++ b/mm/debug_vm_pgtable.c
> @@ -1006,8 +1006,8 @@ static int __init debug_vm_pgtable(void)
>       pud_leaf_tests(pud_aligned, prot);
>  
>  #ifdef CONFIG_NUMA_BALANCING
> -     pte_savedwrite_tests(pte_aligned, prot);
> -     pmd_savedwrite_tests(pmd_aligned, prot);
> +     pte_savedwrite_tests(pte_aligned, protnone);
> +     pmd_savedwrite_tests(pmd_aligned, protnone);
>  #endif
>       pte_special_tests(pte_aligned, prot);
>       pte_protnone_tests(pte_aligned, protnone);
> 

This can be folded back with [PATCH 5/16] which now checks for
CONFIG_NUMA_BALANCING in pxx_savedwrite_tests().