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. > Kirill - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
