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

From: Minchan Kim
Date: Fri Nov 13 2009 - 07:41:42 EST


On Fri, Nov 13, 2009 at 4:30 AM, Mel Gorman <mel@xxxxxxxxx> 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@xxxxxxxxx>

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@xxxxxxxxx>

--
Kind regards,
Minchan Kim
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