Os.freemem() under Linux

[morgan-wild]

Version: 10.15.3 (LTS)
Platform: Linux (Ubuntu server 18.10)
Subsystem: Os.freemem()
Under Linux, Os.freemem() returns the used memory instead of the free one.

[bnoordhuis]

Similar to #27386?

Node.js pulls its information straight from the OS by means of the sysinfo(2) system call. If you see the wrong numbers, you've found a kernel bug.

What does cat /proc/meminfo print?

[morgan-wild]

Thank you for your fast answer!

As asked :

[bnoordhuis]

Okay, I think I have an inkling of the cause.

Can you post the output of uname -a, node -p process.arch and the contents of the memory.limit_in_bytes and memory.soft_limit_in_bytes files in /sys/fs/cgroup/memory? Thanks!

[morgan-wild]

Fore sure, thanks for your help!

[morgan-wild]

I tried the same thing on another distro (Fedora instead of Ubuntu Server) and it works normally.

Ubuntu is in cause.

[bnoordhuis]

My inkling was that this might have been a 32-to-64-bit (or vice versa) kernel compatibility issue but if both kernel and binary are 64 bits, that can't be it. It's probably still a kernel bug, just not that one. :-)

On the bright side, Node.js will start preferring /proc/meminfo over sysinfo(2) in the near future (libuv/libuv#2258) so this issue should cease to exist before too long.

[morgan-wild]

Thank you for your anwser.
I will wait to try again with the future versions of nodejs.