Re: [PATCH] mm: export folio_pte_batch as a couple of modules might need it

Ryan Roberts
2024-02-27T09:11:42Z

On 27/02/2024 03:18, Barry Song wrote:
> On Tue, Feb 27, 2024 at 3:41 PM Barry Song <21cnbao@gmail.com> wrote:
>>
>> From: Barry Song <v-songbaohua@oppo.com>
>>
>> madvise and some others might need folio_pte_batch to check if a range
>> of PTEs are completely mapped to a large folio with contiguous physcial
>> addresses. Let's export it for others to use.
>>
>> Cc: Lance Yang <ioworker0@gmail.com>
>> Cc: Ryan Roberts <ryan.roberts@arm.com>
>> Cc: David Hildenbrand <david@redhat.com>
>
> Hi David, Ryan,
>
> Sorry, I realize I just made a mistake and your tags should be both
> Suggested-by. Please feel
> free to review the patch and give comments. I will fix the tags
> together with addressing your
> review comments in v2.

Don't worry about it. Don't feel you need to update it on my account.

>
>> Cc: Yin Fengwei <fengwei.yin@intel.com>
>> Signed-off-by: Barry Song <v-songbaohua@oppo.com>
>> ---
>> -v1:
>> at least two jobs madv_free and madv_pageout depend on it. To avoid
>> conflicts and dependencies, after discussing with Lance, we prefer
>> this one can land earlier.
>>
>> mm/internal.h | 13 +++++++++++++
>> mm/memory.c | 11 +----------
>> 2 files changed, 14 insertions(+), 10 deletions(-)
>>
>> diff --git a/mm/internal.h b/mm/internal.h
>> index 13b59d384845..8e2bc304f671 100644
>> --- a/mm/internal.h
>> +++ b/mm/internal.h
>> @@ -83,6 +83,19 @@ static inline void *folio_raw_mapping(struct folio *folio)
>> return (void *)(mapping & ~PAGE_MAPPING_FLAGS);
>> }
>>
>> +/* Flags for folio_pte_batch(). */
>> +typedef int __bitwise fpb_t;
>> +
>> +/* Compare PTEs after pte_mkclean(), ignoring the dirty bit. */
>> +#define FPB_IGNORE_DIRTY ((__force fpb_t)BIT(0))
>> +
>> +/* Compare PTEs after pte_clear_soft_dirty(), ignoring the soft-dirty bit. */
>> +#define FPB_IGNORE_SOFT_DIRTY ((__force fpb_t)BIT(1))
>> +
>> +extern int folio_pte_batch(struct folio *folio, unsigned long addr,
>> + pte_t *start_ptep, pte_t pte, int max_nr, fpb_t flags,
>> + bool *any_writable);
>> +
>> void __acct_reclaim_writeback(pg_data_t *pgdat, struct folio *folio,
>> int nr_throttled);
>> static inline void acct_reclaim_writeback(struct folio *folio)
>> diff --git a/mm/memory.c b/mm/memory.c
>> index 1c45b6a42a1b..319b3be05e75 100644
>> --- a/mm/memory.c
>> +++ b/mm/memory.c
>> @@ -953,15 +953,6 @@ static __always_inline void __copy_present_ptes(struct vm_area_struct *dst_vma,
>> set_ptes(dst_vma->vm_mm, addr, dst_pte, pte, nr);
>> }
>>
>> -/* Flags for folio_pte_batch(). */
>> -typedef int __bitwise fpb_t;
>> -
>> -/* Compare PTEs after pte_mkclean(), ignoring the dirty bit. */
>> -#define FPB_IGNORE_DIRTY ((__force fpb_t)BIT(0))
>> -
>> -/* Compare PTEs after pte_clear_soft_dirty(), ignoring the soft-dirty bit. */
>> -#define FPB_IGNORE_SOFT_DIRTY ((__force fpb_t)BIT(1))
>> -
>> static inline pte_t __pte_batch_clear_ignored(pte_t pte, fpb_t flags)
>> {
>> if (flags & FPB_IGNORE_DIRTY)
>> @@ -982,7 +973,7 @@ static inline pte_t __pte_batch_clear_ignored(pte_t pte, fpb_t flags)
>> * If "any_writable" is set, it will indicate if any other PTE besides the
>> * first (given) PTE is writable.
>> */
>> -static inline int folio_pte_batch(struct folio *folio, unsigned long addr,
>> +int folio_pte_batch(struct folio *folio, unsigned long addr,
>> pte_t *start_ptep, pte_t pte, int max_nr, fpb_t flags,
>> bool *any_writable)
>> {
>> --
>> 2.34.1
>>
>
> Thanks
> Barry