Allow coupling decompose() with reduce()

[mrzv]

Issue by Dmitriy Morozov
Wednesday Dec 03, 2014 at 22:08 GMT

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Currently, if the first computation following domain decomposition involves neighborhood communication, it can be included inside the decomposition callback. This is useful in the out-of-core mode, so that all the work is done on a block while it's in memory, rather than taking two passes (and unloading and then re-loading a block on the second foreach()).

The same coupling is not supported if the first communication is a global reduce(). The issue, by and large, is that decomposition callback is passed the neighborhood link. It knows nothing about the global communication pattern.

Probably, the entire decomposition mechanism needs to be rethought. This change would need to be coordinated with issue #3.