Some examples of cache coherence in practice ivy

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Unformatted text preview: ack and forth? Assume that each variable is on its own virtual memory page. What happens if they are both on the same page? does Ivy provide linearizability or sequential consistency? Invariants: 1. every page has exactly one current owner 2. current owner has a copy of the page 3. if mapped r/w by owner, no other copies 4. if mapped r/o by owner, maybe identical other r/o copies 5. manager knows about all copies Ivy does seem to use our two seq consist implementation rules. You can construct a total order always: 1. Each CPU to execute reads/writes in program order, one at a time 2. All writes are in a total order (manager orders them) 3. Once read observes effect of write, it is partially ordered behind it. Order the reads in any total order that obeys the partial order. If you study the protocol carefully, then it is possible to construct an argument that there is no partial order created by the protocol than cannot be embedded in a total order. All CPUs observe all local ops in a local total order (1). All CPUs observe other CPU's operations in order that is consistent with a...
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This document was uploaded on 04/04/2014.

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