There are two main options for performance profiling: perf and gperf.
The perf top option is useful to quickly identify functions that are taking a larger than expected portion of the execution time.:
sudo perf top -p `pidof traffic_server`
For more details use the record subcommand to gather profiling data on the traffic_server process. Using the -g option will gather call stack information. Compiling with -ggdb and -fno-omit-frame-pointer will make it more likely that perf record will gather complete callstacks.:
sudo perf record -g -p `pidof traffic_server`
After gathering profilng data with perf record, use perf report to display the call stacks with their corresponding contribution to total execution time.:
sudo perf report
Gperftools also provides libraries to statistically sample the callstacks of a process. The –with-profile=yes option for configure will link with the gperftools profiling library and add profile stop and profile dump function calls at the beginning and end of the traffic_server main function. The profilng data will be dumped in /tmp/ts.prof.
Once the profiling data file is present, you can use the pprof tool to generate a pdf callgraph of the data to see which call stacks contribute most to the execution time.:
pprof --pdf /opt/trafficserver/9.0/bin/traffic_server ts.prof > prof.pdf