diff options
Diffstat (limited to 'mm/khugepaged.c')
| -rw-r--r-- | mm/khugepaged.c | 65 |
1 files changed, 27 insertions, 38 deletions
diff --git a/mm/khugepaged.c b/mm/khugepaged.c index a7d6cb912b05..6c0185fdd815 100644 --- a/mm/khugepaged.c +++ b/mm/khugepaged.c @@ -481,7 +481,7 @@ int __khugepaged_enter(struct mm_struct *mm) return -ENOMEM; /* __khugepaged_exit() must not run from under us */ - VM_BUG_ON_MM(atomic_read(&mm->mm_users) == 0, mm); + VM_BUG_ON_MM(khugepaged_test_exit(mm), mm); if (unlikely(test_and_set_bit(MMF_VM_HUGEPAGE, &mm->flags))) { free_mm_slot(mm_slot); return 0; @@ -667,7 +667,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, * * The page table that maps the page has been already unlinked * from the page table tree and this process cannot get - * an additinal pin on the page. + * an additional pin on the page. * * New pins can come later if the page is shared across fork, * but not from this process. The other process cannot write to @@ -716,17 +716,17 @@ next: if (pte_write(pteval)) writable = true; } - if (likely(writable)) { - if (likely(referenced)) { - result = SCAN_SUCCEED; - trace_mm_collapse_huge_page_isolate(page, none_or_zero, - referenced, writable, result); - return 1; - } - } else { + + if (unlikely(!writable)) { result = SCAN_PAGE_RO; + } else if (unlikely(!referenced)) { + result = SCAN_LACK_REFERENCED_PAGE; + } else { + result = SCAN_SUCCEED; + trace_mm_collapse_huge_page_isolate(page, none_or_zero, + referenced, writable, result); + return 1; } - out: release_pte_pages(pte, _pte, compound_pagelist); trace_mm_collapse_huge_page_isolate(page, none_or_zero, @@ -809,7 +809,7 @@ static bool khugepaged_scan_abort(int nid) * If node_reclaim_mode is disabled, then no extra effort is made to * allocate memory locally. */ - if (!node_reclaim_mode) + if (!node_reclaim_enabled()) return false; /* If there is a count for this node already, it must be acceptable */ @@ -1128,10 +1128,10 @@ static void collapse_huge_page(struct mm_struct *mm, mmap_write_lock(mm); result = hugepage_vma_revalidate(mm, address, &vma); if (result) - goto out; + goto out_up_write; /* check if the pmd is still valid */ if (mm_find_pmd(mm, address) != pmd) - goto out; + goto out_up_write; anon_vma_lock_write(vma->anon_vma); @@ -1171,7 +1171,7 @@ static void collapse_huge_page(struct mm_struct *mm, spin_unlock(pmd_ptl); anon_vma_unlock_write(vma->anon_vma); result = SCAN_FAIL; - goto out; + goto out_up_write; } /* @@ -1183,19 +1183,18 @@ static void collapse_huge_page(struct mm_struct *mm, __collapse_huge_page_copy(pte, new_page, vma, address, pte_ptl, &compound_pagelist); pte_unmap(pte); + /* + * spin_lock() below is not the equivalent of smp_wmb(), but + * the smp_wmb() inside __SetPageUptodate() can be reused to + * avoid the copy_huge_page writes to become visible after + * the set_pmd_at() write. + */ __SetPageUptodate(new_page); pgtable = pmd_pgtable(_pmd); _pmd = mk_huge_pmd(new_page, vma->vm_page_prot); _pmd = maybe_pmd_mkwrite(pmd_mkdirty(_pmd), vma); - /* - * spin_lock() below is not the equivalent of smp_wmb(), so - * this is needed to avoid the copy_huge_page writes to become - * visible after the set_pmd_at() write. - */ - smp_wmb(); - spin_lock(pmd_ptl); BUG_ON(!pmd_none(*pmd)); page_add_new_anon_rmap(new_page, vma, address, true); @@ -1216,8 +1215,6 @@ out_nolock: mem_cgroup_uncharge(*hpage); trace_mm_collapse_huge_page(mm, isolated, result); return; -out: - goto out_up_write; } static int khugepaged_scan_pmd(struct mm_struct *mm, @@ -1274,10 +1271,6 @@ static int khugepaged_scan_pmd(struct mm_struct *mm, goto out_unmap; } } - if (!pte_present(pteval)) { - result = SCAN_PTE_NON_PRESENT; - goto out_unmap; - } if (pte_uffd_wp(pteval)) { /* * Don't collapse the page if any of the small @@ -1447,7 +1440,7 @@ void collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr) int i; if (!vma || !vma->vm_file || - vma->vm_start > haddr || vma->vm_end < haddr + HPAGE_PMD_SIZE) + !range_in_vma(vma, haddr, haddr + HPAGE_PMD_SIZE)) return; /* @@ -1533,16 +1526,16 @@ abort: goto drop_hpage; } -static int khugepaged_collapse_pte_mapped_thps(struct mm_slot *mm_slot) +static void khugepaged_collapse_pte_mapped_thps(struct mm_slot *mm_slot) { struct mm_struct *mm = mm_slot->mm; int i; if (likely(mm_slot->nr_pte_mapped_thp == 0)) - return 0; + return; if (!mmap_write_trylock(mm)) - return -EBUSY; + return; if (unlikely(khugepaged_test_exit(mm))) goto out; @@ -1553,7 +1546,6 @@ static int khugepaged_collapse_pte_mapped_thps(struct mm_slot *mm_slot) out: mm_slot->nr_pte_mapped_thp = 0; mmap_write_unlock(mm); - return 0; } static void retract_page_tables(struct address_space *mapping, pgoff_t pgoff) @@ -2057,9 +2049,8 @@ static void khugepaged_scan_file(struct mm_struct *mm, BUILD_BUG(); } -static int khugepaged_collapse_pte_mapped_thps(struct mm_slot *mm_slot) +static void khugepaged_collapse_pte_mapped_thps(struct mm_slot *mm_slot) { - return 0; } #endif @@ -2205,11 +2196,9 @@ static void khugepaged_do_scan(void) { struct page *hpage = NULL; unsigned int progress = 0, pass_through_head = 0; - unsigned int pages = khugepaged_pages_to_scan; + unsigned int pages = READ_ONCE(khugepaged_pages_to_scan); bool wait = true; - barrier(); /* write khugepaged_pages_to_scan to local stack */ - lru_add_drain_all(); while (progress < pages) { |