From: "Matthew Wilcox (Oracle)" Subject: mm/khugepaged: stop using vma linked list Use vma iterator & find_vma() instead of vma linked list. Link: https://lkml.kernel.org/r/20220426150616.3937571-54-Liam.Howlett@oracle.com Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Liam R. Howlett Cc: Catalin Marinas Cc: David Howells Cc: Vlastimil Babka Cc: Will Deacon Cc: Yu Zhao Signed-off-by: Andrew Morton --- mm/huge_memory.c | 4 ++-- mm/khugepaged.c | 11 ++++++++--- 2 files changed, 10 insertions(+), 5 deletions(-) --- a/mm/huge_memory.c~mm-khugepaged-stop-using-vma-linked-list +++ a/mm/huge_memory.c @@ -2267,11 +2267,11 @@ void vma_adjust_trans_huge(struct vm_are split_huge_pmd_if_needed(vma, end); /* - * If we're also updating the vma->vm_next->vm_start, + * If we're also updating the next vma vm_start, * check if we need to split it. */ if (adjust_next > 0) { - struct vm_area_struct *next = vma->vm_next; + struct vm_area_struct *next = find_vma(vma->vm_mm, vma->vm_end); unsigned long nstart = next->vm_start; nstart += adjust_next; split_huge_pmd_if_needed(next, nstart); --- a/mm/khugepaged.c~mm-khugepaged-stop-using-vma-linked-list +++ a/mm/khugepaged.c @@ -2119,10 +2119,12 @@ static unsigned int khugepaged_scan_mm_s __releases(&khugepaged_mm_lock) __acquires(&khugepaged_mm_lock) { + struct vma_iterator vmi; struct mm_slot *mm_slot; struct mm_struct *mm; struct vm_area_struct *vma; int progress = 0; + unsigned long address; VM_BUG_ON(!pages); lockdep_assert_held(&khugepaged_mm_lock); @@ -2146,11 +2148,14 @@ static unsigned int khugepaged_scan_mm_s vma = NULL; if (unlikely(!mmap_read_trylock(mm))) goto breakouterloop_mmap_lock; - if (likely(!khugepaged_test_exit(mm))) - vma = find_vma(mm, khugepaged_scan.address); progress++; - for (; vma; vma = vma->vm_next) { + if (unlikely(khugepaged_test_exit(mm))) + goto breakouterloop; + + address = khugepaged_scan.address; + vma_iter_init(&vmi, mm, address); + for_each_vma(vmi, vma) { unsigned long hstart, hend; cond_resched(); _