Quick steps of how to create a flame graph using perf

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
# May also have to do the following:
# (additional reading http://unix.stackexchange.com/questions/14227/do-i-need-root-admin-permissions-to-run-userspace-perf-tool-perf-events-ar )
sudo sysctl kernel.perf_event_paranoid=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

I encountered the following errors:

E: Unable to locate package llvm-3.6
E: Couldn't find any package by regex 'llvm-3.6'
E: Unable to locate package clang-3.6
E: Couldn't find any package by regex 'clang-3.6'
E: Unable to locate package lldb-3.6
E: Couldn't find any package by regex 'lldb-3.6'
E: Unable to locate package libllvm3.6
E: Couldn't find any package by regex 'libllvm3.6'

It seems that llvm/clang/lldb/libllvm 3.6 packages were removed. To fix this issue, I simply switched to 3.5 packages. Hopefully this will help some people.

$ perf script > perf.data.script
[kernel.kallsyms] with build id 9a87d34680d3efd31b5d57f56906d8c2fc38fc5e not found, continuing without symbols
Failed to open /tmp/perf-29438.map, continuing without symbols

What did I miss?

probably the node --perf-basic-prof part

I'm interested in the function calls. There's a lot of module._something, garbage collection and _ZN2v88internal5Scope11LookupLocalEPKNS0_12AstRawStringE stuff in the graph together with function calls. Can I remove all the other stuff and only have the function calls?

^^ +1 for the question above. Thx.