| Subject | Re: [PATCH 01/16] math128: Introduce various 128bit primitives | From | Peter Zijlstra <> | Date | Fri, 26 Oct 2012 11:35:30 +0200 |
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On Fri, 2012-10-26 at 11:24 +0200, Ingo Molnar wrote:
> So can we control this by restricting the users and avoiding the > overflow? > > A 2^64 result should be a *huge* amount of space already for > just about anything.
I _think_ something like: dl_runtime * dl_deadline < U64_MAX, might do that. The question is, is this constraint usable? Simplified that boils down to about 4 seconds each, which sounds pretty much ok for most people -- but such statements usually come back to bite you (640kb anybody...).
Hmm, patch 8 (which adds period support) changes this slightly again. Would it then end up being something like:
dl_period * dl_runtime < U64_MAX && dl_deadline * dl_runtime < U64_MAX
?
Juri, did I get that constraint right and do you know about use-cases where this would be prohibitive?
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