Go Systems Programming

The DTrace utility

Although debugging utilities, such as strace(1) and truss(1), which work on FreeBSD, can trace system calls produced by a process, they can be slow and therefore not appropriate for solving performance problems on busy Unix systems. Another tool named dtrace(1), which uses the DTrace facility, allows you to see what happens behind the scenes on a system-wide basis without the need to modify or recompile anything. It also allows you to work on production systems and watch running programs or server processes dynamically without introducing a big overhead.

This subsection will use the dtruss(1) command-line utility, which is just a dtrace(1) script, that shows the system calls of a process. The output that dtruss(1) generates ...