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Incanam

Using a limited pointer scheme, in this example, we could store ~100 pointers per line in the same amount of space needed by the full bit vector scheme. More practically, we would store less (maybe around 25?). This would drastically reduce the memory cost of a directory based cache coherency system. Yes, it is possible that sometimes data might be stored on more nodes than we have allocated memory for (so more than 25 in my example), but we can deal with this case. The key is, that this case should be very very unlikely, so even if this case performance heavy, the cost should not be significant.