2 research outputs found
Cache-Oblivious VAT-Algorithms
The VAT-model (virtual address translation model) extends the EM-model
(external memory model) and takes the cost of address translation in virtual
memories into account. In this model, the cost of a single memory access may be
logarithmic in the largest address used. We show that the VAT-cost of
cache-oblivious algorithms is only by a constant factor larger than their
EM-cost; this requires a somewhat more stringent tall cache assumption as for
the EM-model
The Cost of Address Translation
Modern computers are not random access machines (RAMs). They have a memory
hierarchy, multiple cores, and virtual memory. In this paper, we address the
computational cost of address translation in virtual memory. Starting point for
our work is the observation that the analysis of some simple algorithms (random
scan of an array, binary search, heapsort) in either the RAM model or the EM
model (external memory model) does not correctly predict growth rates of actual
running times. We propose the VAT model (virtual address translation) to
account for the cost of address translations and analyze the algorithms
mentioned above and others in the model. The predictions agree with the
measurements. We also analyze the VAT-cost of cache-oblivious algorithms.Comment: A extended abstract of this paper was published in the proceedings of
ALENEX13, New Orleans, US