From: Barry Song <v-songbaohua@xxxxxxxx> This patch introduces the pte_need_soft_dirty_wp and pmd_need_soft_dirty_wp helpers to determine if write protection is required for softdirty tracking. This can enhance code readability and improve its overall appearance. These new helpers are utilized in gup, huge_memory, and protect, and are particularly applied in do_swap_page() to optimize a softdirty scenario where mkwrite can still be performed. Suggested-by: David Hildenbrand <david@xxxxxxxxxx> Signed-off-by: Barry Song <v-songbaohua@xxxxxxxx> --- -v1: this is suggested by David here: https://lore.kernel.org/linux-mm/baf84b51-7e8a-4da8-9662-3f5cf14ad6f6@xxxxxxxxxx/ thanks! mm/gup.c | 4 ++-- mm/huge_memory.c | 2 +- mm/internal.h | 10 ++++++++++ mm/memory.c | 2 +- mm/mprotect.c | 2 +- 5 files changed, 15 insertions(+), 5 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 83e279731d1b..756d5416df9c 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -820,7 +820,7 @@ static inline bool can_follow_write_pmd(pmd_t pmd, struct page *page, return false; /* ... and a write-fault isn't required for other reasons. */ - if (vma_soft_dirty_enabled(vma) && !pmd_soft_dirty(pmd)) + if (pmd_need_soft_dirty_wp(vma, pmd)) return false; return !userfaultfd_huge_pmd_wp(vma, pmd); } @@ -941,7 +941,7 @@ static inline bool can_follow_write_pte(pte_t pte, struct page *page, return false; /* ... and a write-fault isn't required for other reasons. */ - if (vma_soft_dirty_enabled(vma) && !pte_soft_dirty(pte)) + if (pte_need_soft_dirty_wp(vma, pte)) return false; return !userfaultfd_pte_wp(vma, pte); } diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 3fbcd77f5957..8fbb62f6e491 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1625,7 +1625,7 @@ static inline bool can_change_pmd_writable(struct vm_area_struct *vma, return false; /* Do we need write faults for softdirty tracking? */ - if (vma_soft_dirty_enabled(vma) && !pmd_soft_dirty(pmd)) + if (pmd_need_soft_dirty_wp(vma, pmd)) return false; /* Do we need write faults for uffd-wp tracking? */ diff --git a/mm/internal.h b/mm/internal.h index 12e95fdf61e9..51551626da68 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -1348,6 +1348,16 @@ static inline bool vma_soft_dirty_enabled(struct vm_area_struct *vma) return !(vma->vm_flags & VM_SOFTDIRTY); } +static inline bool pmd_need_soft_dirty_wp(struct vm_area_struct *vma, pmd_t pmd) +{ + return vma_soft_dirty_enabled(vma) && !pmd_soft_dirty(pmd); +} + +static inline bool pte_need_soft_dirty_wp(struct vm_area_struct *vma, pte_t pte) +{ + return vma_soft_dirty_enabled(vma) && !pte_soft_dirty(pte); +} + static inline void vma_iter_config(struct vma_iterator *vmi, unsigned long index, unsigned long last) { diff --git a/mm/memory.c b/mm/memory.c index db9130488231..6307c43796aa 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -4322,7 +4322,7 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) if (!folio_test_ksm(folio) && (exclusive || folio_ref_count(folio) == 1)) { if ((vma->vm_flags & VM_WRITE) && !userfaultfd_pte_wp(vma, pte) && - !vma_soft_dirty_enabled(vma)) { + !pte_need_soft_dirty_wp(vma, pte)) { pte = pte_mkwrite(pte, vma); if (vmf->flags & FAULT_FLAG_WRITE) { pte = pte_mkdirty(pte); diff --git a/mm/mprotect.c b/mm/mprotect.c index 888ef66468db..5aea9ad11ae1 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -53,7 +53,7 @@ bool can_change_pte_writable(struct vm_area_struct *vma, unsigned long addr, return false; /* Do we need write faults for softdirty tracking? */ - if (vma_soft_dirty_enabled(vma) && !pte_soft_dirty(pte)) + if (pte_need_soft_dirty_wp(vma, pte)) return false; /* Do we need write faults for uffd-wp tracking? */ -- 2.34.1
