Messages in this thread | | | Date | Fri, 28 Aug 2009 23:58:39 +0900 (JST) | Subject | Re: [RFC][PATCH 1/5] memcg: change for softlimit. | From | "KAMEZAWA Hiroyuki" <> |
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Balbir Singh wrote: > * KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> [2009-08-28 > 23:29:09]: > >> Balbir Singh wrote: >> > * KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> [2009-08-28 >> > 16:35:23]: >> > >> >> >> >> >> Current soft-limit RB-tree will be easily broken i.e. not-sorted >> >> correctly >> >> if used under use_hierarchy=1. >> >> >> > >> > Not true, I think the sorted-ness is delayed and is seen when we pick >> > a tree for reclaim. Think of it as being lazy :) >> > >> plz explain how enexpectedly unsorted RB-tree can work sanely. >> >> > > There are two checks built-in > > 1. In the reclaim path (we see how much to reclaim, compared to the > soft limit) > 2. In the dequeue path where we check if we really are over soft limit > that's not a point.
> I did lot of testing with the time based approach and found no broken > cases, I;ve been testing it with the mmotm (event based approach and I > am yet to see a broken case so far). > I'm sorry if I don't understand RB-tree. I think RB-tree is a system which can sort inputs passed by caller one by one and will be in broken state if value of nodes changed while it's in tree. Wrong ? While a subtree is 7 / \ 3 9 And, by some magic, the value can be changed without extract 7 / \ 13 9 The biggest is 13. But the biggest number which will be selecte will be "9".
Thanks, -Kame
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