v8.serialize leaks memory

[JLHwung]

Version

v17.0.1

Platform

21.1.0 Darwin Kernel Version 21.1.0: Wed Oct 13 17:33:01 PDT 2021; root:xnu-8019.41.5~1/RELEASE_ARM64_T6000 arm64

Subsystem

v8

What steps will reproduce the bug?

Run the following snippet

const { serialize } = require("v8");
const { memoryUsage } = process;

for (let i = 0; i < 1 << 22; i++) {
  serialize({});

  if (i % (1 << 15) === 0) {
    console.log(
      `RSS: ${Math.round((memoryUsage().rss / 1024 / 1024) * 100) / 100} MiB`
    );
  }
}

How often does it reproduce? Is there a required condition?

Must reproduce

What is the expected behavior?

The RSS in the stdout should converges to some tens of MiB. For example, if v8.serialize is replaced by JSON.stringify, the RSS is stablized at 33.89MiB.

What do you see instead?

The RSS keeps rising indefinitely.

Additional information

Also affected: v16.0.0

Additional context: babel/babel#13970

[cjihrig]

It doesn't look like you're giving the garbage collector a chance to run. Does the memory get collected once the loop is exited?

[JLHwung]

Does the memory get collected once the loop is exited?

I still see memory surging when I invoke gc every 1 << 15 times.

const { serialize } = require("v8");
const { memoryUsage } = process;

for (let i = 0; i < 1 << 22; i++) {
  serialize({});

  if (i % (1 << 15) === 0) {
    gc();
    console.log(
      `RSS: ${Math.round((memoryUsage().rss / 1024 / 1024) * 100) / 100} MiB`
    );
  }
}

[ppedziwiatr]

Same issue observed on various x86 CPUs and node 16.x and 17x.

The issue doesn't seem to occur on my M1 though.