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diff --git a/cddl/contrib/dtracetoolkit/Examples/shortlived_example.txt b/cddl/contrib/dtracetoolkit/Examples/shortlived_example.txt new file mode 100644 index 0000000..ebe4692 --- /dev/null +++ b/cddl/contrib/dtracetoolkit/Examples/shortlived_example.txt @@ -0,0 +1,57 @@ +The following is an example of the shortlived.d program. +It can measure time spent processing short lived processes, +that may be responsible for heavy load on the system but +are usually difficult to see with sampling tools like prstat. + + + +Here we run in for a few seconds on a server, + + # shortlived.d + Tracing... Hit Ctrl-C to stop. + ^C + short lived processes: 0.456 secs + total sample duration: 9.352 secs + + Total time by process name, + date 12 ms + df 20 ms + ls 40 ms + perl 380 ms + + Total time by PPID, + 3279 452 ms + +In the above output, around 5% of the CPU was lost to short +lived processes - mostly perl. This may be many perl processes, +here we are aggregating on the process name not the instance. + + + +Now shortlived.d is run on a server with a performance problem, + + # uptime + 10:58pm up 5 day(s), 1:28, 1 user, load average: 2.20, 1.81, 1.04 + # + # shortlived.d + Tracing... Hit Ctrl-C to stop. + ^C + short lived processes: 4.546 secs + total sample duration: 9.858 secs + + Total time by process name, + expr 4122 ms + + Total time by PPID, + 3279 4122 ms + # + # ps -p 3279 + PID TTY TIME CMD + 3279 pts/10 0:45 report.sh + +shortlived.d showed that 50% of the CPU was consumed by short lived +processes, all of them the "expr" command, and all having the +parent proccess-ID 3279. We finished by checking PID 3279 to find +it is a Bourne shell script called "report.sh". + + |