2023-07-07 17:10:17

by Yin, Fengwei

[permalink] [raw]
Subject: [RFC PATCH 1/3] mm: add function folio_in_range()

It will be used to check whether the folio is mapped to specific
VMA and whether the mapping address of folio is in the range.

Signed-off-by: Yin Fengwei <[email protected]>
---
mm/internal.h | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)

diff --git a/mm/internal.h b/mm/internal.h
index f1276d90484ad..66117523d7d71 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -585,6 +585,32 @@ extern long faultin_vma_page_range(struct vm_area_struct *vma,
bool write, int *locked);
extern bool mlock_future_ok(struct mm_struct *mm, unsigned long flags,
unsigned long bytes);
+
+static inline bool
+folio_in_range(struct folio *folio, struct vm_area_struct *vma,
+ unsigned long start, unsigned long end)
+{
+ pgoff_t pgoff, addr;
+ unsigned long vma_pglen = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
+
+ VM_WARN_ON_FOLIO(folio_test_ksm(folio), folio);
+ if (start < vma->vm_start)
+ start = vma->vm_start;
+
+ if (end > vma->vm_end)
+ end = vma->vm_end;
+
+ pgoff = folio_pgoff(folio);
+
+ /* if folio start address is not in vma range */
+ if (pgoff < vma->vm_pgoff || pgoff > vma->vm_pgoff + vma_pglen)
+ return false;
+
+ addr = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
+
+ return ((addr >= start) && (addr + folio_size(folio) <= end));
+}
+
/*
* mlock_vma_folio() and munlock_vma_folio():
* should be called with vma's mmap_lock held for read or write,
--
2.39.2



2023-07-08 06:50:37

by Yu Zhao

[permalink] [raw]
Subject: Re: [RFC PATCH 1/3] mm: add function folio_in_range()

On Fri, Jul 7, 2023 at 10:52 AM Yin Fengwei <[email protected]> wrote:
>
> It will be used to check whether the folio is mapped to specific
> VMA and whether the mapping address of folio is in the range.
>
> Signed-off-by: Yin Fengwei <[email protected]>
> ---
> mm/internal.h | 26 ++++++++++++++++++++++++++
> 1 file changed, 26 insertions(+)
>
> diff --git a/mm/internal.h b/mm/internal.h
> index f1276d90484ad..66117523d7d71 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -585,6 +585,32 @@ extern long faultin_vma_page_range(struct vm_area_struct *vma,
> bool write, int *locked);
> extern bool mlock_future_ok(struct mm_struct *mm, unsigned long flags,
> unsigned long bytes);
> +
> +static inline bool
> +folio_in_range(struct folio *folio, struct vm_area_struct *vma,
> + unsigned long start, unsigned long end)

Is there a caller that's not "folio_in_range(folio, vma,
vma->vm_start, vma->vm_end)"?

If not, then just "folio_within_vma(folio, vma)" or a wrapper on top
of folio_in_range().

2023-07-08 07:11:24

by Yin, Fengwei

[permalink] [raw]
Subject: Re: [RFC PATCH 1/3] mm: add function folio_in_range()



On 7/8/2023 1:47 PM, Yu Zhao wrote:
> On Fri, Jul 7, 2023 at 10:52 AM Yin Fengwei <[email protected]> wrote:
>>
>> It will be used to check whether the folio is mapped to specific
>> VMA and whether the mapping address of folio is in the range.
>>
>> Signed-off-by: Yin Fengwei <[email protected]>
>> ---
>> mm/internal.h | 26 ++++++++++++++++++++++++++
>> 1 file changed, 26 insertions(+)
>>
>> diff --git a/mm/internal.h b/mm/internal.h
>> index f1276d90484ad..66117523d7d71 100644
>> --- a/mm/internal.h
>> +++ b/mm/internal.h
>> @@ -585,6 +585,32 @@ extern long faultin_vma_page_range(struct vm_area_struct *vma,
>> bool write, int *locked);
>> extern bool mlock_future_ok(struct mm_struct *mm, unsigned long flags,
>> unsigned long bytes);
>> +
>> +static inline bool
>> +folio_in_range(struct folio *folio, struct vm_area_struct *vma,
>> + unsigned long start, unsigned long end)
>
> Is there a caller that's not "folio_in_range(folio, vma,
> vma->vm_start, vma->vm_end)"?
I believe madvise() will use start/end from user space instead of vma start/end.

>
> If not, then just "folio_within_vma(folio, vma)" or a wrapper on top
> of folio_in_range().
Will add folio_within_vma() based on folio_in_range(). Thanks.

Regards
Yin, Fengwei