Re: [PATCH 7/8] writeback: sync old inodes first in background writeback

KOSAKI Motohiro
2010-07-25T10:43:30Z

Hi

sorry for the delay.

> Will you be picking it up or should I? The changelog should be more or less
> the same as yours and consider it
>
> Signed-off-by: Mel Gorman <mel@csn.ul.ie>
>
> It'd be nice if the original tester is still knocking around and willing
> to confirm the patch resolves his/her problem. I am running this patch on
> my desktop at the moment and it does feel a little smoother but it might be
> my imagination. I had trouble with odd stalls that I never pinned down and
> was attributing to the machine being commonly heavily loaded but I haven't
> noticed them today.
>
> It also needs an Acked-by or Reviewed-by from Kosaki Motohiro as it alters
> logic he introduced in commit [78dc583: vmscan: low order lumpy reclaim also
> should use PAGEOUT_IO_SYNC]

My reviewing doesn't found any bug. however I think original thread have too many guess
and we need to know reproduce way and confirm it.

At least, we need three confirms.
o original issue is still there?
o DEF_PRIORITY/3 is best value?
o Current approach have better performance than Wu's original proposal? (below)

Anyway, please feel free to use my reviewed-by tag.

Thanks.

--- linux-next.orig/mm/vmscan.c 2010-06-24 14:32:03.000000000 +0800
+++ linux-next/mm/vmscan.c 2010-07-22 16:12:34.000000000 +0800
@@ -1650,7 +1650,7 @@ static void set_lumpy_reclaim_mode(int p
*/
if (sc->order > PAGE_ALLOC_COSTLY_ORDER)
sc->lumpy_reclaim_mode = 1;
- else if (sc->order && priority < DEF_PRIORITY - 2)
+ else if (sc->order && priority < DEF_PRIORITY / 2)
sc->lumpy_reclaim_mode = 1;
else
sc->lumpy_reclaim_mode = 0;