Messages in this thread | | | From | KOSAKI Motohiro <> | Subject | Re: [PATCH mmotm] vmscan: handle may_swap more strictly (Re: [PATCH mmotm] vmscan: fix may_swap handling for memcg) | Date | Tue, 9 Jun 2009 16:58:36 +0900 (JST) |
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> Hi, KOSAKI. > > As you know, this problem caused by if condition(priority) in shrink_zone. > Let me have a question. > > Why do we have to prevent scan value calculation when the priority is zero ? > As I know, before split-lru, we didn't do it. > > Is there any specific issue in case of the priority is zero ?
Yes.
example:
get_scan_ratio() return anon:80%, file=20%. and the system have 10000 anon pages and 10000 file pages.
shrink_zone() picked up 8000 anon pages and 2000 file pages. it mean 8000 file pages aren't scanned at all.
Oops, it can makes OOM-killer although system have droppable file cache.
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