Messages in this thread | | | Date | Tue, 21 Apr 2009 16:39:54 +0900 | From | Minchan Kim <> | Subject | Re: [PATCH] low order lumpy reclaim also should use PAGEOUT_IO_SYNC. |
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On Tue, 21 Apr 2009 16:21:18 +0900 (JST) KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> wrote:
> > Hi, Kosaki-san. > > > > On Tue, 21 Apr 2009 14:22:27 +0900 (JST) > > KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> wrote: > > > > > Subject: [PATCH] low order lumpy reclaim also should use PAGEOUT_IO_SYNC. > > > > > > commit 33c120ed2843090e2bd316de1588b8bf8b96cbde (more aggressively use lumpy reclaim) > > > change lumpy reclaim using condition. but it isn't enough change. > > > > > > lumpy reclaim don't only mean isolate neighber page, but also do pageout as synchronous. > > > this patch does it. > > > > I agree. > > > > Andi added synchronous lumpy reclaim with c661b078fd62abe06fd11fab4ac5e4eeafe26b6d. > > At that time, lumpy reclaim is not agressive. > > His intension is just for high-order users.(above PAGE_ALLOC_COSTLY_ORDER). > > > > After some time, Rik added aggressive lumpy reclaim with 33c120ed2843090e2bd316de1588b8bf8b96cbde. > > His intension is that do lumpy reclaim when high-order users and trouble getting a small set of contiguous pages. > > > > So we also have to add synchronous pageout for small set of contiguous pages. > > Nice catch!. > > > > Reviewed-by: Minchan Kim <Minchan.kim@gmail.com> > > > > BTW, Do you have any number ? > > No. > > Actually, this logic only run when system is strongly memory stavation > or fragment. not normal case. > > At that time, another slowdown thing hide synchronous reclaim latency, I think. >
Yes. I think it's hard measure, too. I was just out of curiosity if server guy have a any benchmark method. ;-)
-- Kinds Regards Minchan Kim
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