Messages in this thread | | | Date | Fri, 3 Jun 2011 08:15:39 +0900 | Subject | Re: [patch 7/8] vmscan: memcg-aware unevictable page rescue scanner | From | Hiroyuki Kamezawa <> |
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2011年6月3日金曜日 Johannes Weiner hannes@cmpxchg.org: > On Fri, Jun 03, 2011 at 07:01:34AM +0900, Hiroyuki Kamezawa wrote: >> 2011/6/3 Ying Han <yinghan@google.com>: >> > On Thu, Jun 2, 2011 at 6:27 AM, Hiroyuki Kamezawa >> > <kamezawa.hiroyuki@gmail.com> wrote: >> >> 2011/6/1 Johannes Weiner <hannes@cmpxchg.org>: >> >>> Once the per-memcg lru lists are exclusive, the unevictable page >> >>> rescue scanner can no longer work on the global zone lru lists. >> >>> >> >>> This converts it to go through all memcgs and scan their respective >> >>> unevictable lists instead. >> >>> >> >>> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> >> >> >> >> Hm, isn't it better to have only one GLOBAL LRU for unevictable pages ? >> >> memcg only needs counter for unevictable pages and LRU is not necessary >> >> to be per memcg because we don't reclaim it... >> > >> > Hmm. Are we suggesting to keep one un-evictable LRU list for all >> > memcgs? So we will have >> > exclusive lru only for file and anon. If so, we are not done to make >> > all the lru list being exclusive >> > which is critical later to improve the zone->lru_lock contention >> > across the memcgs >> > >> considering lrulock, yes, maybe you're right. > > That's one of the complications. > >> > Sorry If i misinterpret the suggestion here >> > >> >> My concern is I don't know for what purpose this function is used .. > > I am not sure how it's supposed to be used, either. But it's > documented to be a 'really big hammer' and it's kicked off from > userspace. So I suppose having the thing go through all memcgs bears > a low risk of being a problem. My suggestion is we go that way until > someone complains.
Ok. Please go with memcg local unevictable lru.
-kame
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