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):

# expose kernel pointers to perf
# because of /proc/kallsyms; with kernel.kpt_restrict=1, the symbol addresses are hidden
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:)" | ../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:)" | ../FlameGraph/stackcollapse-perf.pl | grep "uv_run" > out.perf-folded

prep-script.sh

#!/bin/bash

sh /etc/lsb-release

wget -O - http://llvm.org/apt/llvm-snapshot.gpg.key|sudo apt-key add -

apt-add-repository "deb http://llvm.org/apt/${DISTRIB_CODENAME}/ llvm-toolchain-${DISTRIB_CODENAME} main"

apt-get update

apt-get -y upgrade

apt-get -y install make build-essential linux-tools-common elfutils libelf-dev flex bison libunwind8 libunwind8-dev libaudit-dev libdw-dev binutils-dev libnuma-dev libslang2-dev asciidoc llvm-3.6 clang-3.6 lldb-3.6 libllvm3.6 subversion libc6-dev-i386 libgtk2.0-dev libperl-dev python-dev git tmux nginx gdb apache2-utils

ln -s /usr/bin/clang-3.6 /usr/bin/clang

ln -s /usr/bin/clang++-3.6 /usr/bin/clang++

ln -s /usr/bin/lldb-3.6 /usr/bin/lldb

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

. ~/.bash_aliases

chmod 777 /usr/share/nginx/html
ln -s /usr/share/nginx/html www

mkdir sources

cd sources

wget https://github.com/joyent/node/archive/v0.11.13.tar.gz

tar xvf v0.11.13.tar.gz

rm v0.11.13.tar.gz

mv node-0.11.13 node

cd node

./configure --gdb

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-3.15.6.tar.gz

#tar xvf linux-3.15.6.tar.gz

#rm linux-3.15.6.tar.gz

#cd linux-3.15.6/tools/perf/

#make -f Makefile.perf install prefix=/usr