Reported CPU usage not matching System Monitor usage

[RafaelKr]

Describe the bug
I just wanted to check if #2050 is fixed with v1.8.2. The CPU usage issue is indeed fixed, but the usage report of all processes in process-compose doesn't match with the usage report of my System Monitor:

I'm using Linux Mint 22.1 Cinnamon.

Note: I get ✨ devenv 1.8.2 is newer than devenv input (1.8.1) in devenv.lock. Run 'devenv update' to sync. when running devenv as 1.8.2 is not available in github:NixOS/nixpkgs/nixpkgs-unstable yet.

Is there anything I should do to clear caches or something?

Edit: I first thought memory usage is also wrongly reported, but I can toggle Show Memory in IEC, then the Resident Memory sum of devenv-tasks + children matches the reported usage:

To reproduce
Maybe it can be reproduced with any devenv.nix, maybe it's just on my system, let me know!

Version
devenv 1.8.2 (x86_64-linux)

[sandydoo]

I patched devenv-nixpkgs/rolling with process-compose 1.73. This version disables the recursive process monitoring by default until they figure out how to do so in a way that doesn't use an entire CPU core per process-compose instance: F1bonacc1/process-compose#352

[RafaelKr]

Thanks, good to know! As long as I don't see any real performance degredation I'll keep using process-compose 1.64.1 and wait for NixOS/nixpkgs#432850 to land.

[sandydoo]

1.64.1 is fine, it just uses a whole core for the CPU usage metrics and people have been complaining about that.

NixOS/nixpkgs#432850 is what I released on rolling. It disables the more accurate CPU usage metrics.

In any case, the "more accurate" metrics aren't even that accurate. Last time I checked, they use a time window for averaging and that time window is from the start of the process.