From: David Hildenbrand <david@redhat.com>
From: David Hildenbrand <david@redhat.com>
Let's add variants to be used where "full" does not apply -- which will
be the majority of cases in the future. "full" really only applies if
we are about to tear down a full MM.
Use get_and_clear_ptes() in existing code, clear_ptes() users will
be added next.
Should we make these inline functions instead and add separate docs?
Probably not worth it for now.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Dev Jain <dev.jain@arm.com>
---
arch/arm64/mm/mmu.c | 2 +-
include/linux/pgtable.h | 6 ++++++
mm/mremap.c | 2 +-
mm/rmap.c | 2 +-
4 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index abd9725796e9..20a89ab97dc5 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1528,7 +1528,7 @@ early_initcall(prevent_bootmem_remove_init);
pte_t modify_prot_start_ptes(struct vm_area_struct *vma, unsigned long addr,
pte_t *ptep, unsigned int nr)
{
- pte_t pte = get_and_clear_full_ptes(vma->vm_mm, addr, ptep, nr, /* full = */ 0);
+ pte_t pte = get_and_clear_ptes(vma->vm_mm, addr, ptep, nr);
if (alternative_has_cap_unlikely(ARM64_WORKAROUND_2645198)) {
/*
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index e3b99920be05..e45986b54277 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -736,6 +736,9 @@ static inline pte_t get_and_clear_full_ptes(struct mm_struct *mm,
}
#endif
+#define get_and_clear_ptes(_mm, _addr, _ptep, _nr) \
+ get_and_clear_full_ptes(_mm, _addr, _ptep, _nr, 0)
+
#ifndef clear_full_ptes
/**
* clear_full_ptes - Clear present PTEs that map consecutive pages of the same
@@ -768,6 +771,9 @@ static inline void clear_full_ptes(struct mm_struct *mm, unsigned long addr,
}
#endif
+#define clear_ptes(_mm, _addr, _ptep, _nr) \
+ clear_full_ptes(_mm, _addr, _ptep, _nr, 0)
+
/*
* If two threads concurrently fault at the same page, the thread that
* won the race updates the PTE and its local TLB/Cache. The other thread
diff --git a/mm/mremap.c b/mm/mremap.c
index ac39845e9718..677a4d744df9 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -280,7 +280,7 @@ static int move_ptes(struct pagetable_move_control *pmc,
old_pte, max_nr_ptes);
force_flush = true;
}
- pte = get_and_clear_full_ptes(mm, old_addr, old_ptep, nr_ptes, 0);
+ pte = get_and_clear_ptes(mm, old_addr, old_ptep, nr_ptes);
pte = move_pte(pte, old_addr, new_addr);
pte = move_soft_dirty_pte(pte);
diff --git a/mm/rmap.c b/mm/rmap.c
index f93ce27132ab..568198e9efc2 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -2036,7 +2036,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
flush_cache_range(vma, address, end_addr);
/* Nuke the page table entry. */
- pteval = get_and_clear_full_ptes(mm, address, pvmw.pte, nr_pages, 0);
+ pteval = get_and_clear_ptes(mm, address, pvmw.pte, nr_pages);
/*
* We clear the PTE but do not flush so potentially
* a remote CPU could still be writing to the folio.
--
2.30.2
On 2025/7/22 23:05, Dev Jain wrote:
> From: David Hildenbrand <david@redhat.com>
>
> From: David Hildenbrand <david@redhat.com>
>
> Let's add variants to be used where "full" does not apply -- which will
> be the majority of cases in the future. "full" really only applies if
> we are about to tear down a full MM.
>
> Use get_and_clear_ptes() in existing code, clear_ptes() users will
> be added next.
>
> Should we make these inline functions instead and add separate docs?
> Probably not worth it for now.
>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> Signed-off-by: Dev Jain <dev.jain@arm.com>
LGTM.
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
> ---
> arch/arm64/mm/mmu.c | 2 +-
> include/linux/pgtable.h | 6 ++++++
> mm/mremap.c | 2 +-
> mm/rmap.c | 2 +-
> 4 files changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index abd9725796e9..20a89ab97dc5 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -1528,7 +1528,7 @@ early_initcall(prevent_bootmem_remove_init);
> pte_t modify_prot_start_ptes(struct vm_area_struct *vma, unsigned long addr,
> pte_t *ptep, unsigned int nr)
> {
> - pte_t pte = get_and_clear_full_ptes(vma->vm_mm, addr, ptep, nr, /* full = */ 0);
> + pte_t pte = get_and_clear_ptes(vma->vm_mm, addr, ptep, nr);
>
> if (alternative_has_cap_unlikely(ARM64_WORKAROUND_2645198)) {
> /*
> diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
> index e3b99920be05..e45986b54277 100644
> --- a/include/linux/pgtable.h
> +++ b/include/linux/pgtable.h
> @@ -736,6 +736,9 @@ static inline pte_t get_and_clear_full_ptes(struct mm_struct *mm,
> }
> #endif
>
> +#define get_and_clear_ptes(_mm, _addr, _ptep, _nr) \
> + get_and_clear_full_ptes(_mm, _addr, _ptep, _nr, 0)
> +
> #ifndef clear_full_ptes
> /**
> * clear_full_ptes - Clear present PTEs that map consecutive pages of the same
> @@ -768,6 +771,9 @@ static inline void clear_full_ptes(struct mm_struct *mm, unsigned long addr,
> }
> #endif
>
> +#define clear_ptes(_mm, _addr, _ptep, _nr) \
> + clear_full_ptes(_mm, _addr, _ptep, _nr, 0)
> +
> /*
> * If two threads concurrently fault at the same page, the thread that
> * won the race updates the PTE and its local TLB/Cache. The other thread
> diff --git a/mm/mremap.c b/mm/mremap.c
> index ac39845e9718..677a4d744df9 100644
> --- a/mm/mremap.c
> +++ b/mm/mremap.c
> @@ -280,7 +280,7 @@ static int move_ptes(struct pagetable_move_control *pmc,
> old_pte, max_nr_ptes);
> force_flush = true;
> }
> - pte = get_and_clear_full_ptes(mm, old_addr, old_ptep, nr_ptes, 0);
> + pte = get_and_clear_ptes(mm, old_addr, old_ptep, nr_ptes);
> pte = move_pte(pte, old_addr, new_addr);
> pte = move_soft_dirty_pte(pte);
>
> diff --git a/mm/rmap.c b/mm/rmap.c
> index f93ce27132ab..568198e9efc2 100644
> --- a/mm/rmap.c
> +++ b/mm/rmap.c
> @@ -2036,7 +2036,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
> flush_cache_range(vma, address, end_addr);
>
> /* Nuke the page table entry. */
> - pteval = get_and_clear_full_ptes(mm, address, pvmw.pte, nr_pages, 0);
> + pteval = get_and_clear_ptes(mm, address, pvmw.pte, nr_pages);
> /*
> * We clear the PTE but do not flush so potentially
> * a remote CPU could still be writing to the folio.
On Tue, 22 Jul 2025 20:35:57 +0530 Dev Jain <dev.jain@arm.com> wrote: > Let's add variants to be used where "full" does not apply -- which will > be the majority of cases in the future. "full" really only applies if > we are about to tear down a full MM. > > Use get_and_clear_ptes() in existing code, clear_ptes() users will > be added next. > > Should we make these inline functions instead and add separate docs? inlined functions would be preferable. > Probably not worth it for now. Well, as David has called for a v4 I suggest you make that change. Thanks, I'll queue the series in mm-new for a bit of testing.
On 23/07/25 2:17 am, Andrew Morton wrote: > On Tue, 22 Jul 2025 20:35:57 +0530 Dev Jain <dev.jain@arm.com> wrote: > >> Let's add variants to be used where "full" does not apply -- which will >> be the majority of cases in the future. "full" really only applies if >> we are about to tear down a full MM. >> >> Use get_and_clear_ptes() in existing code, clear_ptes() users will >> be added next. >> >> Should we make these inline functions instead and add separate docs? > inlined functions would be preferable. > >> Probably not worth it for now. > Well, as David has called for a v4 I suggest you make that change. > > Thanks, I'll queue the series in mm-new for a bit of testing. Thanks. I'll post v4 later in the day.
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