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

Balbir Singh
2009-08-28T15:08:33Z

* KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> [2009-08-29 00:06:23]:

> Balbir Singh wrote:
> > * KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> [2009-08-28
> > 23:40:56]:
> >
> >> KAMEZAWA Hiroyuki wrote:
> >> > Balbir Singh wrote:
> >> >> But Bob and Mike might need to set soft limits between themselves. if
> >> >> soft limit of gold is 1G and bob needs to be close to 750M and mike
> >> >> 250M, how do we do it without supporting what we have today?
> >> >>
> >> > Don't use hierarchy or don't use softlimit.
> >> > (I never think fine-grain soft limit can be useful.)
> >> >
> >> > Anyway, I have to modify unnecessary hacks for res_counter of
> >> softlimit.
> >> > plz allow modification. that's bad.
> >> > I postpone RB-tree breakage problem, plz explain it or fix it by
> >> yourself.
> >> >
> >> I changed my mind....per-zone RB-tree is also broken ;)
> >>
> >> Why I don't like broken system is a function which a user can't
> >> know/calculate how-it-works is of no use in mission critical systems.
> >>
> >> I'd like to think how-to-fix it with better algorithm. Maybe RB-tree
> >> is not a choice.
> >>
> >
> > Soft limits are not meant for mission critical work :-) Soft limits is
> > best effort and not a guaranteed resource allocation mechanism. I've
> > mentioned in previous emails how we recover if we find the data is
> > stale
> >
> yes. but can you explain how selection will be done to users ?
> I can't.
>

>From a user point, we get what we set, but the timelines can be a
little longer.

--
Balbir