1.perf
Perf is a built-in performance analysis (profiling) in the Linux kernel source tree tool. It is based on the principle of sampling event to event-based performance, support for processor performance analysis of relevant performance indicators and operating system-related performance indicators. It may be used to locate hot spots to find the code performance bottlenecks. linux2.6 and later comes with the tool, capable of handling almost all performance-related events.