Re: [RFC, PATCH 0/5] Going forward with Resource Management - A cpucontroller

From: Martin Bligh
Date: Mon Aug 07 2006 - 15:44:40 EST


Rohit Seth wrote:
On Mon, 2006-08-07 at 11:43 -0700, Dave Hansen wrote:

On Mon, 2006-08-07 at 11:31 -0700, Rohit Seth wrote:

I think it is not a problem for OpenVZ because there is not that much
of
sharing going between containers as you mentioned (btw, this least
amount of sharing is a very good thing). Though I'm not sure if one
has
to go to the extent of doing fractions with memory accounting. If the
containers are set up in such a way that there is some sharing across
containers then it is okay to be unfair and charge one of those
containers for the specific resource completely.

Right, and if you do reclaim against containers which are over their
limits, the containers being unfairly charged will tend to get hit
first. But, once this happens, I would hope that the ownership of those
shared pages should settle out among all of the users.



I think there is lot of simplicity and value add by charging one
container (even unfairly) for one resource completely. This puts the
onus on system admin to set up the containers appropriately.

It also saves you from maintaining huge lists against each page.

Worse case, you want to bill everyone who opens that address_space
equally. But the semantics on exit still suck.

What was Alan's quote again? "unfair, unreliable, inefficient ...
pick at least one out of the three". or something like that.

M.
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