Messages in this thread | | | Date | Fri, 9 Mar 2007 14:29:22 +0100 | From | Herbert Poetzl <> | Subject | Re: [PATCH 1/2] rcfs core patch |
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On Fri, Mar 09, 2007 at 12:07:27PM +0300, Kirill Korotaev wrote: >> nobody actually cares about a precise accounting and >> calculating shares or partitions of whatever resource, >> all that matters is that you have a way to prevent a >> potential hostile environment from sucking up all your >> resources (or even a single one) resulting in a DoS
> This is not true. People care. Reasons: > - resource planning > - fairness > - guarantees
let me make that a little more clear ...
_nobody_ cares wether a shared memory page is accounted as full page or as fraction of a page (depending on the number of guests sharing it) as long as the accounted amount is substracted correctly when the page is disposed
so there _is_ a difference between _false_ accounting (which seems what you are referring to in the next paragraph) and imprecise, but consistant accounting (which is what I was talking about)
best, Herbert
> What you talk is about security only. Not the above issues. > So good precision is required. If there is no precision at all, > security sucks as well and can be exploited, e.g. for CPU > schedulers doing an accounting based on jiffies accounting in > scheduler_tick() it is easy to build an application consuming > 90% of CPU, but ~0% from scheduler POV.
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