Re: [PATCH] vmscan: page_check_references() check low order lumpy reclaim properly

[Andrew Morton <akpm@linux-foundation.org>]

On Fri, 16 Apr 2010 12:16:18 +0900 (JST)
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> wrote:

> If vmscan is under lumpy reclaim mode, it have to ignore referenced bit
> for making contenious free pages. but current page_check_references()
> doesn't.
> 
> Fixes it.
> 
> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
> ---
>  mm/vmscan.c |   32 +++++++++++++++++---------------
>  1 files changed, 17 insertions(+), 15 deletions(-)
> 
> diff --git a/mm/vmscan.c b/mm/vmscan.c
> index 3ff3311..13d9546 100644
> --- a/mm/vmscan.c
> +++ b/mm/vmscan.c
> @@ -77,6 +77,8 @@ struct scan_control {
>  
>  	int order;
>  
> +	int lumpy_reclaim;
> +

Needs a comment explaining its role, please.  Something like "direct
this reclaim run to perform lumpy reclaim"?

A clearer name might be "lumpy_relcaim_mode"?

Making it a `bool' would clarify things too.