Re: [PATCH v4 36/66] um: Remove vma linked list walk

From: Vlastimil Babka
Date: Tue Jan 18 2022 - 13:41:15 EST


On 12/1/21 15:30, Liam Howlett wrote:
> From: "Liam R. Howlett" <Liam.Howlett@xxxxxxxxxx>
>
> Use the VMA iterator instead.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
> ---
> arch/um/kernel/tlb.c | 14 ++++++--------
> 1 file changed, 6 insertions(+), 8 deletions(-)
>
> diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c
> index bc38f79ca3a3..25f043037d76 100644
> --- a/arch/um/kernel/tlb.c
> +++ b/arch/um/kernel/tlb.c
> @@ -584,21 +584,19 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
>
> void flush_tlb_mm(struct mm_struct *mm)
> {
> - struct vm_area_struct *vma = mm->mmap;
> + struct vm_area_struct *vma;
> + VMA_ITERATOR(vmi, mm, 0);
>
> - while (vma != NULL) {
> + for_each_vma(vmi, vma)
> fix_range(mm, vma->vm_start, vma->vm_end, 0);
> - vma = vma->vm_next;
> - }
> }
>
> void force_flush_all(void)
> {
> struct mm_struct *mm = current->mm;
> - struct vm_area_struct *vma = mm->mmap;
> + struct vm_area_struct *vma;
> + MA_STATE(mas, &mm->mm_mt, 0, 0);
>
> - while (vma != NULL) {
> + mas_for_each(&mas, vma, ULONG_MAX)

Is there a reason to use the iterator in one case and mas_for_each in the other?

> fix_range(mm, vma->vm_start, vma->vm_end, 1);
> - vma = vma->vm_next;
> - }
> }