Re: [PATCH -mm 2/6] rmap: always add new vmas at the end

From: Andrew Morton
Date: Tue Jun 22 2010 - 17:08:41 EST


On Mon, 21 Jun 2010 16:33:49 -0400
Rik van Riel <riel@xxxxxxxxxx> wrote:

> From: Andrea Arcangeli <aarcange@xxxxxxxxxx>
> Subject: always add new vmas at the end
>
> Make sure to always add new VMAs at the end of the list. This
> is important so rmap_walk does not miss a VMA that was created
> during the rmap_walk.
>
> The old code got this right most of the time due to luck, but
> was buggy when anon_vma_prepare reused a mergeable anon_vma.
>
> Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
> Signed-off-by: Rik van Riel <riel@xxxxxxxxxx>
> ---
>
> diff --git a/mm/rmap.c b/mm/rmap.c
> --- a/mm/rmap.c
> +++ b/mm/rmap.c
> @@ -149,7 +149,7 @@ int anon_vma_prepare(struct vm_area_stru
> avc->anon_vma = anon_vma;
> avc->vma = vma;
> list_add(&avc->same_vma, &vma->anon_vma_chain);
> - list_add(&avc->same_anon_vma, &anon_vma->head);
> + list_add_tail(&avc->same_anon_vma, &anon_vma->head);
> allocated = NULL;
> avc = NULL;
> }

Should this go into 2.6.35?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/