A generalization of the tree-LRU (pseudo-LRU, PLRU) method for cache line replacement selection in an N-way set-associative cache is described. In this method, a line is selected for replacement within a set using a logical multi-way tree, where the leaf nodes of the tree represent lines in a set, and where if the branching factor of a given node in the logical tree at a given level is k, then the state of the node is represented by one of k! (k factorial) logical states representing an access order of the nodes below the given node in the logical tree. Results showing the degree to which these methods approximate LRU replacement are presented.
By: John T. Robinson
Published in: RC23332 in 2004
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