[PATCH v3 1/2] mm: introduce pmd_install() helper
From: Qi Zheng <hidden>
Date: 2021-09-01 10:27:52
Also in:
linux-mm, lkml
Subsystem:
memory management, memory management - core, page cache, the rest · Maintainers:
Andrew Morton, David Hildenbrand, Matthew Wilcox, Linus Torvalds
Currently we have three times the same few lines repeated in the code. Deduplicate them by newly introduced pmd_install() helper. Signed-off-by: Qi Zheng <redacted> Reviewed-by: David Hildenbrand <redacted> Reviewed-by: Muchun Song <redacted> Acked-by: Kirill A. Shutemov <redacted> --- mm/filemap.c | 11 ++--------- mm/internal.h | 1 + mm/memory.c | 34 ++++++++++++++++------------------ 3 files changed, 19 insertions(+), 27 deletions(-)
diff --git a/mm/filemap.c b/mm/filemap.c
index c90b6e4984c9..923cbba1bf37 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c@@ -3209,15 +3209,8 @@ static bool filemap_map_pmd(struct vm_fault *vmf, struct page *page) } } - if (pmd_none(*vmf->pmd)) { - vmf->ptl = pmd_lock(mm, vmf->pmd); - if (likely(pmd_none(*vmf->pmd))) { - mm_inc_nr_ptes(mm); - pmd_populate(mm, vmf->pmd, vmf->prealloc_pte); - vmf->prealloc_pte = NULL; - } - spin_unlock(vmf->ptl); - } + if (pmd_none(*vmf->pmd)) + pmd_install(mm, vmf->pmd, &vmf->prealloc_pte); /* See comment in handle_pte_fault() */ if (pmd_devmap_trans_unstable(vmf->pmd)) {
diff --git a/mm/internal.h b/mm/internal.h
index b1001ebeb286..18256e32a14c 100644
--- a/mm/internal.h
+++ b/mm/internal.h@@ -47,6 +47,7 @@ bool __folio_end_writeback(struct folio *folio); void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma, unsigned long floor, unsigned long ceiling); +void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte); static inline bool can_madv_lru_vma(struct vm_area_struct *vma) {
diff --git a/mm/memory.c b/mm/memory.c
index 39e7a1495c3c..ef7b1762e996 100644
--- a/mm/memory.c
+++ b/mm/memory.c@@ -433,9 +433,20 @@ void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *vma, } } +void pmd_install(struct mm_struct *mm, pmd_t *pmd, pgtable_t *pte) +{ + spinlock_t *ptl = pmd_lock(mm, pmd); + + if (likely(pmd_none(*pmd))) { /* Has another populated it ? */ + mm_inc_nr_ptes(mm); + pmd_populate(mm, pmd, *pte); + *pte = NULL; + } + spin_unlock(ptl); +} + int __pte_alloc(struct mm_struct *mm, pmd_t *pmd) { - spinlock_t *ptl; pgtable_t new = pte_alloc_one(mm); if (!new) return -ENOMEM;
@@ -455,13 +466,7 @@ int __pte_alloc(struct mm_struct *mm, pmd_t *pmd) */ smp_wmb(); /* Could be smp_wmb__xxx(before|after)_spin_lock */ - ptl = pmd_lock(mm, pmd); - if (likely(pmd_none(*pmd))) { /* Has another populated it ? */ - mm_inc_nr_ptes(mm); - pmd_populate(mm, pmd, new); - new = NULL; - } - spin_unlock(ptl); + pmd_install(mm, pmd, &new); if (new) pte_free(mm, new); return 0;
@@ -4027,17 +4032,10 @@ vm_fault_t finish_fault(struct vm_fault *vmf) return ret; } - if (vmf->prealloc_pte) { - vmf->ptl = pmd_lock(vma->vm_mm, vmf->pmd); - if (likely(pmd_none(*vmf->pmd))) { - mm_inc_nr_ptes(vma->vm_mm); - pmd_populate(vma->vm_mm, vmf->pmd, vmf->prealloc_pte); - vmf->prealloc_pte = NULL; - } - spin_unlock(vmf->ptl); - } else if (unlikely(pte_alloc(vma->vm_mm, vmf->pmd))) { + if (vmf->prealloc_pte) + pmd_install(vma->vm_mm, vmf->pmd, &vmf->prealloc_pte); + else if (unlikely(pte_alloc(vma->vm_mm, vmf->pmd))) return VM_FAULT_OOM; - } } /* See comment in handle_pte_fault() */
--
2.11.0