Summarize the capabilities provided by the Unix ptrace mechanism. What is the principal difference between the Unix prof and gprof tools? For the purposes of performance analysis, summarize the...

Summarize the capabilities provided by the Unix ptrace mechanism. What is the principal difference between the Unix prof and gprof tools? For the purposes of performance analysis, summarize the relative strengths and limitations of statistical sampling, instrumentation, and hardware performance counters. Explain why statistical sampling and instrumentation might profitably be used together.