follow_page() doesn't need it, but we'll start to need it when unifying gup
for hugetlb.
Signed-off-by: Peter Xu <[email protected]>
---
include/linux/hugetlb.h | 8 +++++---
mm/gup.c | 3 ++-
mm/hugetlb.c | 4 +++-
3 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 21f942025fec..0d6f389d98de 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -131,7 +131,8 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma,
int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *,
struct vm_area_struct *, struct vm_area_struct *);
struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
- unsigned long address, unsigned int flags);
+ unsigned long address, unsigned int flags,
+ unsigned int *page_mask);
long follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *,
struct page **, unsigned long *, unsigned long *,
long, unsigned int, int *);
@@ -297,8 +298,9 @@ static inline void adjust_range_if_pmd_sharing_possible(
{
}
-static inline struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
- unsigned long address, unsigned int flags)
+static inline struct page *hugetlb_follow_page_mask(
+ struct vm_area_struct *vma, unsigned long address, unsigned int flags,
+ unsigned int *page_mask)
{
BUILD_BUG(); /* should never be compiled in if !CONFIG_HUGETLB_PAGE*/
}
diff --git a/mm/gup.c b/mm/gup.c
index aa0668505d61..8d59ae4554e7 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -794,7 +794,8 @@ static struct page *follow_page_mask(struct vm_area_struct *vma,
* Ordinary GUP uses follow_hugetlb_page for hugetlb processing.
*/
if (is_vm_hugetlb_page(vma))
- return hugetlb_follow_page_mask(vma, address, flags);
+ return hugetlb_follow_page_mask(vma, address, flags,
+ &ctx->page_mask);
pgd = pgd_offset(mm, address);
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 9c261921b2cf..f037eaf9d819 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -6457,7 +6457,8 @@ static inline bool __follow_hugetlb_must_fault(struct vm_area_struct *vma,
}
struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
- unsigned long address, unsigned int flags)
+ unsigned long address, unsigned int flags,
+ unsigned int *page_mask)
{
struct hstate *h = hstate_vma(vma);
struct mm_struct *mm = vma->vm_mm;
@@ -6506,6 +6507,7 @@ struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
* because we hold the ptl lock and have verified pte_present().
*/
WARN_ON_ONCE(try_grab_page(page, flags));
+ *page_mask = huge_page_mask(h);
}
out:
spin_unlock(ptl);
--
2.40.1
On 06/13/23 17:53, Peter Xu wrote:
> follow_page() doesn't need it, but we'll start to need it when unifying gup
> for hugetlb.
>
> Signed-off-by: Peter Xu <[email protected]>
> ---
> include/linux/hugetlb.h | 8 +++++---
> mm/gup.c | 3 ++-
> mm/hugetlb.c | 4 +++-
> 3 files changed, 10 insertions(+), 5 deletions(-)
Reviewed-by: Mike Kravetz <[email protected]>
--
Mike Kravetz
>
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 21f942025fec..0d6f389d98de 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -131,7 +131,8 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma,
> int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *,
> struct vm_area_struct *, struct vm_area_struct *);
> struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
> - unsigned long address, unsigned int flags);
> + unsigned long address, unsigned int flags,
> + unsigned int *page_mask);
> long follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *,
> struct page **, unsigned long *, unsigned long *,
> long, unsigned int, int *);
> @@ -297,8 +298,9 @@ static inline void adjust_range_if_pmd_sharing_possible(
> {
> }
>
> -static inline struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
> - unsigned long address, unsigned int flags)
> +static inline struct page *hugetlb_follow_page_mask(
> + struct vm_area_struct *vma, unsigned long address, unsigned int flags,
> + unsigned int *page_mask)
> {
> BUILD_BUG(); /* should never be compiled in if !CONFIG_HUGETLB_PAGE*/
> }
> diff --git a/mm/gup.c b/mm/gup.c
> index aa0668505d61..8d59ae4554e7 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -794,7 +794,8 @@ static struct page *follow_page_mask(struct vm_area_struct *vma,
> * Ordinary GUP uses follow_hugetlb_page for hugetlb processing.
> */
> if (is_vm_hugetlb_page(vma))
> - return hugetlb_follow_page_mask(vma, address, flags);
> + return hugetlb_follow_page_mask(vma, address, flags,
> + &ctx->page_mask);
>
> pgd = pgd_offset(mm, address);
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 9c261921b2cf..f037eaf9d819 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -6457,7 +6457,8 @@ static inline bool __follow_hugetlb_must_fault(struct vm_area_struct *vma,
> }
>
> struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
> - unsigned long address, unsigned int flags)
> + unsigned long address, unsigned int flags,
> + unsigned int *page_mask)
> {
> struct hstate *h = hstate_vma(vma);
> struct mm_struct *mm = vma->vm_mm;
> @@ -6506,6 +6507,7 @@ struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
> * because we hold the ptl lock and have verified pte_present().
> */
> WARN_ON_ONCE(try_grab_page(page, flags));
> + *page_mask = huge_page_mask(h);
> }
> out:
> spin_unlock(ptl);
> --
> 2.40.1
>
On 13.06.23 23:53, Peter Xu wrote:
> follow_page() doesn't need it, but we'll start to need it when unifying gup
> for hugetlb.
>
> Signed-off-by: Peter Xu <[email protected]>
> ---
> include/linux/hugetlb.h | 8 +++++---
> mm/gup.c | 3 ++-
> mm/hugetlb.c | 4 +++-
> 3 files changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 21f942025fec..0d6f389d98de 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -131,7 +131,8 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma,
> int copy_hugetlb_page_range(struct mm_struct *, struct mm_struct *,
> struct vm_area_struct *, struct vm_area_struct *);
> struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
> - unsigned long address, unsigned int flags);
> + unsigned long address, unsigned int flags,
> + unsigned int *page_mask);
> long follow_hugetlb_page(struct mm_struct *, struct vm_area_struct *,
> struct page **, unsigned long *, unsigned long *,
> long, unsigned int, int *);
> @@ -297,8 +298,9 @@ static inline void adjust_range_if_pmd_sharing_possible(
> {
> }
>
> -static inline struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
> - unsigned long address, unsigned int flags)
> +static inline struct page *hugetlb_follow_page_mask(
> + struct vm_area_struct *vma, unsigned long address, unsigned int flags,
> + unsigned int *page_mask)
> {
> BUILD_BUG(); /* should never be compiled in if !CONFIG_HUGETLB_PAGE*/
> }
> diff --git a/mm/gup.c b/mm/gup.c
> index aa0668505d61..8d59ae4554e7 100644
> --- a/mm/gup.c
> +++ b/mm/gup.c
> @@ -794,7 +794,8 @@ static struct page *follow_page_mask(struct vm_area_struct *vma,
> * Ordinary GUP uses follow_hugetlb_page for hugetlb processing.
> */
> if (is_vm_hugetlb_page(vma))
> - return hugetlb_follow_page_mask(vma, address, flags);
> + return hugetlb_follow_page_mask(vma, address, flags,
> + &ctx->page_mask);
>
> pgd = pgd_offset(mm, address);
>
> diff --git a/mm/hugetlb.c b/mm/hugetlb.c
> index 9c261921b2cf..f037eaf9d819 100644
> --- a/mm/hugetlb.c
> +++ b/mm/hugetlb.c
> @@ -6457,7 +6457,8 @@ static inline bool __follow_hugetlb_must_fault(struct vm_area_struct *vma,
> }
>
> struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
> - unsigned long address, unsigned int flags)
> + unsigned long address, unsigned int flags,
> + unsigned int *page_mask)
> {
> struct hstate *h = hstate_vma(vma);
> struct mm_struct *mm = vma->vm_mm;
> @@ -6506,6 +6507,7 @@ struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
> * because we hold the ptl lock and have verified pte_present().
> */
> WARN_ON_ONCE(try_grab_page(page, flags));
> + *page_mask = huge_page_mask(h);
> }
> out:
> spin_unlock(ptl);
Reviewed-by: David Hildenbrand <[email protected]>
--
Cheers,
David / dhildenb
On Tue, Jun 13, 2023 at 05:53:42PM -0400, Peter Xu wrote:
> @@ -6506,6 +6507,7 @@ struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
> * because we hold the ptl lock and have verified pte_present().
> */
> WARN_ON_ONCE(try_grab_page(page, flags));
> + *page_mask = huge_page_mask(h);
Sorry, I was wrong this line. It should be:
*page_mask = ~huge_page_mask(h) >> PAGE_SHIFT;
This can be exposed if we bypass fast-gup and also specify pin npages>1.
Probably overlooked in my initial round and I'd guess fast-gup just all
succeeded there..
I'll temporarily drop the R-bs for this patch, so reviewers can have
another closer look in this one.
--
Peter Xu
On 19.06.23 23:43, Peter Xu wrote:
> On Tue, Jun 13, 2023 at 05:53:42PM -0400, Peter Xu wrote:
>> @@ -6506,6 +6507,7 @@ struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
>> * because we hold the ptl lock and have verified pte_present().
>> */
>> WARN_ON_ONCE(try_grab_page(page, flags));
>> + *page_mask = huge_page_mask(h);
>
> Sorry, I was wrong this line. It should be:
>
> *page_mask = ~huge_page_mask(h) >> PAGE_SHIFT;
>
That's ... surprising. It feels like either page_mask or
huge_page_mask() has a misleading name ....
h->mask = ~(huge_page_size(h) - 1);
For PMDs, we do
ctx->page_mask = HPAGE_PMD_NR - 1;
Maybe
*page_mask = PHYS_PFN(huge_page_size(h)) - 1;
Would be clearer.
I guess "page_mask" should actually be "pfn_mask" ... but the meaning
regarding PAGE_MASK are still inverted ...
--
Cheers,
David / dhildenb
On Tue, Jun 20, 2023 at 09:01:23AM +0200, David Hildenbrand wrote:
> On 19.06.23 23:43, Peter Xu wrote:
> > On Tue, Jun 13, 2023 at 05:53:42PM -0400, Peter Xu wrote:
> > > @@ -6506,6 +6507,7 @@ struct page *hugetlb_follow_page_mask(struct vm_area_struct *vma,
> > > * because we hold the ptl lock and have verified pte_present().
> > > */
> > > WARN_ON_ONCE(try_grab_page(page, flags));
> > > + *page_mask = huge_page_mask(h);
> >
> > Sorry, I was wrong this line. It should be:
> >
> > *page_mask = ~huge_page_mask(h) >> PAGE_SHIFT;
> >
>
> That's ... surprising. It feels like either page_mask or huge_page_mask()
> has a misleading name ....
>
> h->mask = ~(huge_page_size(h) - 1);
>
>
> For PMDs, we do
>
> ctx->page_mask = HPAGE_PMD_NR - 1;
>
>
> Maybe
>
> *page_mask = PHYS_PFN(huge_page_size(h)) - 1;
>
> Would be clearer.
Since I just posted a new version.. I'll see whether I should get that
cleaned up in a new one.
>
> I guess "page_mask" should actually be "pfn_mask" ... but the meaning
> regarding PAGE_MASK are still inverted ...
Yes, pfn_mask can be at least slightly better. I can add a patch to rename
it, or we can also do it on top as cleanups.
Thanks,
--
Peter Xu