CPU profiling with perf

CPU profiling with linux perf tool.

Based on Brendan Gregg's posts: 1 2

Install

• linux perf tool

  sudo apt install linux-perf
  

  Make all events available to all users:

  echo "kernel.perf_event_paranoid = -1" | sudo tee -a /etc/sysctl.conf
  reboot
  

• flamegraphs

  git clone https://github.com/brendangregg/FlameGraph
  

Usage

• record data

  Sample for 60 seconds at 99 Hertz (-F 99) across all CPUs (-a), capturing stack traces so that a call graph (-g) of function ancestry can be generated later.

  The samples are saved in a perf.data file, which are read by perf script.

  For the entire system:

  perf record -F 99 -a -g -- sleep 60
  

  For specific process:

  perf record -F 99 -p 12345 -a -g -- sleep 60
  

  See more one-liners for recording here

• process data

  perf script > out.perf
  

• collapse stack

  ./FlameGraph/stackcollapse-perf.pl out.perf > out.folded
  

• generate flamegraph

  ./FlameGraph/flamegraph.pl --inverted out.folded > out.svg
  

• view flamegraph(for example with chromium)

  chromium out.svg