CONCURRENT PROCESS MONITORING WITH NO REFERENCE SIGNATURES

A simple, inexpensive and time/space efficient signature technique for process monitoring is presented. In this technique, a known signature function is applied to the instruction stream at compilation phase an d when the accumulated signature forms an m-out-of-n code, the corresp onding instructions are tagged. Error checking is done at run-time by monitoring the signatures accumulated at the tagged locations to deter mine whether they form m-out-of-n codes. This approach of signature ch ecking does not require the embedding of reference signatures at compi lation, thereby leading to savings in memory as well as in execution t ime. The m-out-of-n code approach offers high error coverage and contr ollable latency. The results of the experiments conducted to verify th e controllability of the latency are discussed. One of the distinguish ing features of the proposed scheme is the elimination of reference si gnatures, which are the main source of memory and time overhead in the existing techniques.