Re: [PATCH 5/5] vmscan: Take order into consideration when deciding if kswapd is in trouble

[Minchan Kim <minchan.kim-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

On Fri, Nov 13, 2009 at 4:30 AM, Mel Gorman <mel-wPRd99KPJ+uzQB+pC5nmwQ@public.gmane.org> wrote:
> If reclaim fails to make sufficient progress, the priority is raised.
> Once the priority is higher, kswapd starts waiting on congestion.
> However, on systems with large numbers of high-order atomics due to
> crappy network cards, it's important that kswapd keep working in
> parallel to save their sorry ass.
>
> This patch takes into account the order kswapd is reclaiming at before
> waiting on congestion. The higher the order, the longer it is before
> kswapd considers itself to be in trouble. The impact is that kswapd
> works harder in parallel rather than depending on direct reclaimers or
> atomic allocations to fail.
>
> Signed-off-by: Mel Gorman <mel-wPRd99KPJ+uzQB+pC5nmwQ@public.gmane.org>

It's make sense to me.
It can help high order atomic allocation which is a big problem of allocator. :)

Thanks Mel.

Reviewed-by: Minchan Kim <minchan.kim-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>

-- 
Kind regards,
Minchan Kim