Re: [RFC][PATCH 1/5] memcg: change for softlimit.

Balbir Singh
2009-08-28T14:45:43Z

* 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

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).

--
Balbir