Inconsistency in translation lookaside buffer

摘要

A multiprocessor which shares the memory among processors and uses multiples translation lookaside buffers (TLBs) can face various problems. One such problem is the problem of inconsistency which may occur when the page table entry (PTE) is updated because of the multiple copies of same page table entry in various TLBs. Commonly, the inconsistency problem exists in virtually tagged caches, which keep page table entry information, like reference bit, dirty bit and protection bit, in every cache line. This paper describes the problem of translation lookaside buffer inconsistency in multiprocessors with shared memory. First of all problem statement is given. Then paper presents the argument that inconsistency problem exist even when in cache address translation removes a separate translation lookaside buffer. Later, the TLB inconsistency classification and causes of inconsistency because of operating system operations are discussed.