Re: [ckrm-tech] [RFC][PATCH 5/8] RSS controller task migration support

Patrick.Le-Dot
2006-11-17T14:42:14Z

On Fri, 17 Nov 2006 14:05:13 +0000
> ...
> There are two reasons for wanting memory guarantees
>
> #1 To be sure a user can't toast the entire box but just their own
> compartment (eg web hosting)

Well, this seems not a situation to add a guarantee to this user
but a limit...

> ...
> #2 To ensure all apps continue to make progress

or to ensure that a job is ready to work without to have to pay the
cost of a lot of pagination in...

>> If the limit is a "hard limit" then we have implemented reservation and
>> this is too strict.
>
> Thats fundamentally a judgement based on your particular workload and
> constraints.
Nop.
You can read this on the wiki page...

I'm just saying that the implementation of guarantee with limits seems to
be not enough for #2.

> If I am web hosting then I don't generally care if my end
> users compartment blows up under excess load, I care that the other 200
> customers using the box don't suffer and all phone me to complain.

I agree : limit is necessary and should be a "hard limit" (even if the
controler needs an internal threeshold like a "soft limit" to decide to
wakeup the kswapd).
But this is not the topic (not yet:-)

Patrick