node --perf-basic-prof index.js - No information about JavaScript functions, only v8.

[vlopp]

• Version: v14.6.0
• Platform: Linux rd 5.4.0-42-generic Tracking / Assuring Compatibility #46-Ubuntu SMP Fri Jul 10 00:24:02 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

What steps will reproduce the bug?

Following this tutorial from the official node website.

perf record -e cycles:u -g -- node --perf-basic-prof index.js

This generates perf.data and a /tmp/perf-somenumbers.js file.

index.js:

function FunctionA1() {
  FunctionB2();
}

function FunctionB2() {
  console.log("Hello!");
}

FunctionA1();

perf script > perfs.out

3. Now, this doesn't return any results, although I'd expect to see FunctionA1 calls logged by perf.

cat perfs.out | grep FunctionA1

Perf was installing via

sudo apt install linux-tools-generic

What is the expected behavior?

Javascript functions, such as FunctionA1, are visible in the captured info.

[mmarchini]

V8 changed their optimization pipeline on Node.js v8.x, which makes it harder for perf to capture some functions. Starting on Node.js v10.x, a new flag was added (--interpreted-frames-native-stack) that works around that limitation (the flag must be used alongside --perf-basic-prof). For more details, refer to https://nodejs.org/en/docs/guides/diagnostics-flamegraph/#perf-output-issues and for historical context: nodejs/diagnostics#407 (comment)

[bnoordhuis]

Closing as answered, let me know if there's reason to reopen.