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Approach 1
The first approach recognizes that throttling a node makes its
synchronization time negligible. When a node is being throttled, it
is made to be slower than all other nodes so as to expose
data dependencies. Consequently, the think time between I/Os
is all computation (e.g., node 1 in Figure 2 does not have
to wait on nodes 0 and 2, because node 1 is the slowest node).
The primary advantage of this approach is that it can be used even
if an application is using ``untraceable'' synchronization
mechanisms such as shared memory. The disadvantage is that I/O
sampling can affect the computation calculation. This is discussed more
in Section 5.
Michael Mesnier
2006-12-22