uftrace for Erlang BEAM VM
This document is written by Yunseong Kim known as Paran Lee
Erlang is a programming language and runtime system for building massively scalable soft real-time systems with requirements on high availability.
OTP is a set of Erlang libraries, which consists of the Erlang runtime system, a number of ready-to-use components mainly written in Erlang, and a set of design principles for Erlang programs.
BEAM is Virtual Machine that run Erlang and Elixr Programming language.
git clone https://github.com/erlang/otp.git
cd otp
export CFLAGS="-g3 -O0 -fno-omit-frame-pointer -pg"
export CXXFLAGS="-g3 -O0 -fno-omit-frame-pointer -pg"
export ERL_TOP=$(pwd)
./configure
time make -j96 | tee make-build.log
make -j96 -C erts/emulator clean
time make -j96 -C erts/emulator debug asan gprof 2>&1 | tee erts_emulator-build.log
make -j96 -C erts/lib_src clean
time make -j96 -C erts/lib_src debug asan gprof 2>&1 | tee erts_lib_src-build.log
make -j96 -C lib/crypto/c_src clean
time make -j96 -C lib/crypto/c_src debug asan gprof 2>&1 | tee lib_crypto_c_src-build.log
escript
Test code factorial.erl
otp$ cat factorial.erl
#!/usr/bin/env escript
%% -*- erlang -*-
%%! -sname factorial -mnesia debug verbose
main([String]) ->
try
N = list_to_integer(String),
F = fac(N),
io:format("factorial ~w = ~w\n", [N,F])
catch
_:_ ->
usage()
end;
main(_) ->
usage().
usage() ->
io:format("usage: factorial integer\n"),
halt(1).
fac(0) -> 1;
fac(N) -> N * fac(N-1).
Trace the factorial erlang program.
$ uftrace record --no-sched --no-libcall -N ^std -t 20us bin/escript factorial.erl 3
$ uftrace replay
# DURATION TID FUNCTION
[ 22055] | main() {
28.099 ms [ 22055] | start_epmd_daemon();
[ 22055] | /* linux:task-name (comm="beam.smp") */
[ 22055] | _GLOBAL__sub_I_BeamGlobalAssembler::emitPtrs() {
253.384 us [ 22055] | __static_initialization_and_destruction_0();
256.612 us [ 22055] | } /* _GLOBAL__sub_I_BeamGlobalAssembler::emitPtrs */
[ 22055] | main() {
[ 22055] | erl_start() {
[ 22055] | early_init() {
[ 22055] | erts_pre_early_init_cpu_topology() {
[ 22055] | erts_cpu_info_create() {
[ 22055] | erts_cpu_info_update() {
[ 22055] | read_cpu_quota() {
[ 22055] | get_cgroup_path() {
47.290 us [ 22055] | get_cgroup_child_path();
102.354 us [ 22055] | } /* get_cgroup_path */
126.461 us [ 22055] | } /* read_cpu_quota */
198.301 us [ 22055] | } /* erts_cpu_info_update */
199.631 us [ 22055] | } /* erts_cpu_info_create */
202.694 us [ 22055] | } /* erts_pre_early_init_cpu_topology */
[ 22055] | erts_sys_pre_init() {
[ 22055] | erts_thr_init() {
[ 22055] | ethr_init() {
[ 22055] | ethr_init_common__() {
[ 22055] | erts_cpu_info_create() {
[ 22055] | erts_cpu_info_update() {
[ 22055] | read_cpu_quota() {
38.797 us [ 22055] | get_cgroup_path();
51.421 us [ 22055] | } /* read_cpu_quota */
79.093 us [ 22055] | } /* erts_cpu_info_update */
79.429 us [ 22055] | } /* erts_cpu_info_create */
86.339 us [ 22055] | } /* ethr_init_common__ */
96.058 us [ 22055] | } /* ethr_init */
97.334 us [ 22055] | } /* erts_thr_init */
126.595 us [ 22055] | } /* erts_sys_pre_init */
[ 22055] | erts_early_init_scheduling() {
62.984 us [ 22055] | aux_work_timeout_early_init();
70.929 us [ 22055] | } /* erts_early_init_scheduling */
[ 22055] | erts_alloc_init() {
419.831 us [ 22055] | erts_mseg_init();
[ 22055] | start_au_allocator() {
[ 22055] | erts_gfalc_start() {
We can use Perfetto.
alias uftrace_json="$HOME/uftrace/uftrace dump --libmcount-path=$HOME/uftrace --chrome > dump.json"
