Quick note: Generate flamegraph for Crystal app
Quick note for me to remember how to generate flamegraphs to profile Crystal lang app. Let’s see how it works…
Flamegraph?
Installation
$ brew install flamegraph
$ ls /opt/homebrew/Cellar/flamegraph/1.0_1/bin
difffolded.pl pkgsplit-perf.pl stackcollapse-elfutils.pl stackcollapse-instruments.pl stackcollapse-perf-sched.awk stackcollapse-recursive.pl stackcollapse-vsprof.pl
files.pl range-perf.pl stackcollapse-gdb.pl stackcollapse-jstack.pl stackcollapse-perf.pl stackcollapse-sample.awk stackcollapse-vtune.pl
flamegraph.pl stackcollapse-aix.pl stackcollapse-go.pl stackcollapse-ljp.awk stackcollapse-pmc.pl stackcollapse-stap.pl stackcollapse.pl
Profile
Run application and extract Process ID(PID), that requires to record data.
For example I am looking to debug my app that has name crystal-run:
$ sudo dtrace -x ustackframes=100 -n 'profile-97 /pid == $(pgrep -n crystal-run)/ { @[ustack()] = count(); } tick-60s { exit(0); }' -o out.user_stacks
$ stackcollapse.pl out.user_stacks | flamegraph.pl > user.svg