Firefox 78 will have a process manager

In the nightly builds of Firefox that will form the June 30th release of Firefox 78, added service page "about:processes", which proposed process manager. The new page allows you to evaluate which handler processes are running, which internal threads are running in each process, and how much each thread and process consumes CPU and memory resources.

Separates the CPU consumption of code in user space and at the kernel level (when executing system calls). Separately, data on the consumption of resident and virtual memory is displayed, and the dynamics of changes in memory consumption is also shown. Displays information about the gpu (rendering), web, webisolated (separate tabs), extension, privilegedabout, socket, and browser (main process) processes.

From previously available service diagnostic pages you can note about: support, about: performance, about: memory, about: networking, about: cache, about: webrtc и about: telemetry.

Source: opennet.ru