Re: [PATCHv3 1/3] mm: Introduce vma_init()

[Linus Torvalds]

On Wed, Jul 25, 2018 at 5:39 AM Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> wrote:
>
> There are few more:
>
> arch/arm64/include/asm/tlb.h:   struct vm_area_struct vma = { .vm_mm = tlb->mm, };
> arch/arm64/mm/hugetlbpage.c:    struct vm_area_struct vma = { .vm_mm = mm };
> arch/arm64/mm/hugetlbpage.c:    struct vm_area_struct vma = { .vm_mm = mm };

We probably do not care. These are not "real" vma's and are never used
as such. They are literally just fake vmas for the "flush_tlb()"
machinery, which won't ever really cause any VM activity and will just
call back to the architecture TLB flushing routines.

They initialize vm_mm exactly because that's how the mm is passed down
to the tlb flushing (we pass the whole vma because some architectures
than have special flags in vm_flags too that can affect how the TLB
gets flushed - ie "only flush ITLB if it's an execute-only vma" etc).

Using "vma_init()" on them is only confusing, I think.

                 Linus