I was excited at first, and then realized this is a kernel patch and not a userland tool. Boooo. FB says "PSI tracks three major system resources — CPU, memory,

I was excited at first, and then realized this is a kernel patch and not a userland tool. Boooo. FB says "PSI tracks three major system resources — CPU, memory, and I/O — and provides a canonical view into how the usage of these resources changes over time." It should have been possible to do this in userland and make this (somewhat) kernel version-independent. I'm sure I'll use this once there's OSes running a stable kernel with these patches, but I don't run non-vendor kernels in production [unless I'm forced to], and depending on kernel features makes it hard to support legacy systems.