Re: [PATCH 4/6] mm: kswapd: Reset kswapd_max_order andclasszone_idx after reading

From: Mel Gorman
Date: Fri Dec 10 2010 - 05:43:25 EST


On Fri, Dec 10, 2010 at 01:03:01AM +0900, Minchan Kim wrote:
> On Fri, Dec 10, 2010 at 12:59 AM, Minchan Kim <minchan.kim@xxxxxxxxx> wrote:
> > On Thu, Dec 09, 2010 at 11:18:18AM +0000, Mel Gorman wrote:
> >> When kswapd wakes up, it reads its order and classzone from pgdat and
> >> calls balance_pgdat. While its awake, it potentially reclaimes at a high
> >> order and a low classzone index. This might have been a once-off that
> >> was not required by subsequent callers. However, because the pgdat
> >> values were not reset, they remain artifically high while
> >> balance_pgdat() is running and potentially kswapd enters a second
> >> unnecessary reclaim cycle. Reset the pgdat order and classzone index
> >> after reading.
> >>
> >> Signed-off-by: Mel Gorman <mel@xxxxxxxxx>
> > Reviewed-by: Minchan Kim <minchan.kim@xxxxxxxxx>
>
> Nitpick.
> Shouldn't this patch be merged with 1/6?
>

I don't think so as it's a standalone fix. For example, if this was
merged on its own, the "order" should still be reset after reading.

--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab
--
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/