Re: [PATCH v4 10/12] mm/rmap: refactor anon folio unmap in try_to_unmap_one

[Dev Jain]

On 16/06/26 7:40 pm, David Hildenbrand (Arm) wrote:
> On 5/26/26 08:36, Dev Jain wrote:
>> Refactor anonymous folio unmap to ttu_anon_folio.
> 
> Given that the !folio_test_swapbacked() case remains in the caller, should we
> make it clearer and call it
> 
> 	ttu_anon_swapbacked_folio()
> 
> Or alternatively, factor complete anon folio handling out (incl. lazyfree handling)?

Hmm I'll see if this can be done.

> 
>>
>> No functional change intended.
>>
>> Signed-off-by: Dev Jain <dev.jain@xxxxxxx>
>> ---
>>  mm/rmap.c | 116 ++++++++++++++++++++++++++++++++----------------------
>>  1 file changed, 68 insertions(+), 48 deletions(-)
>>
>> diff --git a/mm/rmap.c b/mm/rmap.c
>> index c0e385882f562..b1639bad8e27f 100644
>> --- a/mm/rmap.c
>> +++ b/mm/rmap.c
>> @@ -2136,6 +2136,70 @@ static inline bool ttu_lazyfree_folio(struct vm_area_struct *vma,
>>  	return true;
>>  }
>>  
>> +static inline void set_swp_pte_at(struct mm_struct *mm, unsigned long address,
>> +		pte_t *ptep, swp_entry_t entry, pte_t pteval, bool anon_exclusive)
>> +{
>> +	pte_t swp_pte = swp_entry_to_pte(entry);
>> +
>> +	if (anon_exclusive)
>> +		swp_pte = pte_swp_mkexclusive(swp_pte);
>> +
>> +	if (likely(pte_present(pteval))) {
>> +		if (pte_soft_dirty(pteval))
>> +			swp_pte = pte_swp_mksoft_dirty(swp_pte);
>> +		if (pte_uffd_wp(pteval))
>> +			swp_pte = pte_swp_mkuffd_wp(swp_pte);
>> +	} else {
>> +		/* Device-exclusive entry */
>> +		if (pte_swp_soft_dirty(pteval))
>> +			swp_pte = pte_swp_mksoft_dirty(swp_pte);
>> +		if (pte_swp_uffd_wp(pteval))
>> +			swp_pte = pte_swp_mkuffd_wp(swp_pte);
>> +	}
>> +
>> +	set_pte_at(mm, address, ptep, swp_pte);
>> +}
>> +
>> +static inline bool ttu_anon_folio(struct vm_area_struct *vma, struct folio *folio,
>> +		struct page *subpage, unsigned long address, pte_t *ptep,
>> +		pte_t pteval)
>> +{
>> +	bool anon_exclusive = folio_test_anon(folio) && PageAnonExclusive(subpage);
> 
> "subpage" ;)

I'll change that.

> 
> Can be const.

Okay.

> 
> [...]
> 
>>  		} else {
>>  			/*
>>  			 * This is a locked file-backed folio,
> 
> Happy to see that function shrink a bit ...
>