perf-flame-graph-notes.md

The prep-script.sh will setup the latest Node and install the latest perf version on your Linux box.

When you want to generate the flame graph, run the following (folder locations taken from install script):

sudo sysctl kernel/kptr_restrict=0

perf record -i -g -e cycles:u -- ~/sources/node/node --perf-basic-prof script.js

perf script | egrep -v "( __libc_start| LazyCompile | v8::internal::| Builtin:| Stub:| LoadIC:|\[unknown\]| LoadPolymorphicIC:)" | sed 's/ LazyCompile:[*~]\?/ /' | ~/sources/FlameGraph/stackcollapse-perf.pl > out.perf-folded

~/sources/FlameGraph/flamegraph.pl out.perf-folded > node-flame.svg

The data munging is to help expose the most important bits. There is still some play that I'm working with, but right now it seems to be working.

Alternatives:

perf script | egrep -v "( __libc_start|node::Start\(| LazyCompile | Builtin:| Stub:| LoadIC:|\[unknown\]| LoadPolymorphicIC:)" | ~/sources/FlameGraph/stackcollapse-perf.pl | grep "uv_run" > out.perf-folded

perf script | egrep -v "( __libc_start|node::Start\(| LazyCompile | v8::internal::| Builtin:| Stub:| LoadIC:|\[unknown\]| LoadPolymorphicIC:)" | ~/sources/FlameGraph/stackcollapse-perf.pl | grep "uv_run" > out.perf-folded

Profile a running node app

run your node app with --perf-basic-prof flag. Then profile like this.

perf record -i -g -e cycles:u -p PID

prep-script.sh

#!/bin/bash

apt-get update

apt-get -y upgrade

apt-get -y install make build-essential elfutils libelf-dev flex bison libunwind8 libunwind8-dev libaudit-dev libdw-dev binutils-dev libnuma-dev libslang2-dev asciidoc llvm-3.4 clang-3.4 subversion libc6-dev-i386 libgtk2.0-dev libperl-dev python-dev git

echo 'export CC=clang' > .bash_aliases
echo 'export CXX=clang++' >> .bash_aliases
echo 'export GYP_DEFINES="clang=1"' >> .bash_aliases

mkdir sources

cd sources

wget https://github.com/joyent/node/archive/master.tar.gz

tar xvf master.tar.gz

rm master.tar.gz

mv node-master node

cd node

./configure

make

make install

cd ~/sources

wget https://github.com/brendangregg/FlameGraph/archive/master.tar.gz

tar xvf master.tar.gz

rm master.tar.gz

mv FlameGraph-master FlameGraph

cd ~/sources

wget https://www.kernel.org/pub/linux/kernel/v3.x/linux-3.13.6.tar.gz

tar xvf linux-3.13.6.tar.gz

rm linux-3.13.6.tar.gz

cd linux-3.13.6/tools/perf/

make -f Makefile.perf install prefix=/usr