Re: [PATCH] rmap: add exclusively owned pages to the newest anon_vma

[Minchan Kim]

On Thu, Apr 15, 2010 at 6:59 AM, Rik van Riel <riel@xxxxxxxxxx> wrote:
> The recent anon_vma fixes cause many anonymous pages to end up
> in the parent process anon_vma, even when the page is exclusively
> owned by the current process.
>
> Adding exclusively owned anonymous pages to the top anon_vma
> reduces rmap scanning overhead, especially in workloads with
> forking servers.
>
> This patch adds a parameter to __page_set_anon_rmap that can
> be used to indicate whether or not the added page is exclusively
> owned by the current process.
>
> Pages added through page_add_new_anon_rmap are exclusively
> owned by the current process, and can be added to the top
> anon_vma.
>
> Pages added through page_add_anon_rmap can be either shared
> or exclusively owned, so we do the conservative thing and
> add it to the oldest anon_vma.
>
> A next step would be to add the exclusive parameter to
> page_add_anon_rmap, to be used from functions where we do
> know for sure whether a page is exclusively owned.
>
> Signed-off-by: Rik van Riel <riel@xxxxxxxxxx>
Reviewed-by: Minchan Kim <minchan.kim@xxxxxxxxx>


-- 
Kind regards,
Minchan Kim
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