Following are examples of running tcl_cputime.d. Here it runs while we execute Code/Tcl/func_slow.tcl # tcl_cputime.d Tracing... Hit Ctrl-C to end. ^C Top 10 counts, PID TYPE NAME COUNT 16038 cmd set 2 16038 cmd namespace 3 16038 cmd puts 3 16038 cmd lappend 4 16038 cmd lsearch 4 16038 cmd if 8 16038 cmd info 11 16038 cmd file 12 16038 cmd proc 12 0 total - 82 Top 10 exclusive on-CPU times (us), PID TYPE NAME TOTAL 16038 cmd namespace 130 16038 cmd puts 232 16038 cmd if 310 16038 cmd tclInit 315 16038 cmd file 411 16038 cmd source 760 16038 proc func_a 535521 16038 proc func_b 1071082 16038 proc func_c 1619323 0 total - 3228670 Top 10 inclusive on-CPU times (us), PID TYPE NAME TOTAL 16038 cmd source 1359 16038 cmd uplevel 1367 16038 proc tclInit 1865 16038 cmd tclInit 2180 16038 proc func_c 1619360 16038 cmd func_c 1619404 16038 proc func_b 2690525 16038 cmd func_b 2690568 16038 proc func_a 3226247 16038 cmd func_a 3226275 We can see that the output is in three sections. The first section represents the ten most commonly executed commands while the script is tracing. The exclusive function on-CPU times show that func_a spent around 0.5 seconds on-CPU, func_b spent about 1.0 seconds, and func_c, 1.6 seconds. This excludes time spent in other procedures or commands. The inclusive function on-CPU times show the time spent by these procedures in total, including the time spent in other functions called, and since func_a called func_b which called func_c, these times make sense. These on-CPU times are the time the thread spent running on a CPU, from when the function began to when it completed. This does not include time spent off-CPU time such as sleeping for I/O or waiting for scheduling. On-CPU times are useful for showing who is causing the CPUs to be busy. See Notes/ALLoncpu_notes.txt for more details. Also see Notes/ALLexclusive_notes.txt and Notes/ALLinclusive_notes.txt for a detailed explanation of exclusive vs inclusive function time.