Linux PSI memory pressure: what it really measures
What PSI actually measures Pressure Stall Information (PSI) was merged in Linux 4.20 (commit e970d0aa0bb98a9d4b9a2e3887da44b79f7b46c8 upstream — Johannes Weiner’s psi-tracking series). It is not a load average, it is not a throughput number, and it is emphatically not a “how busy is the CPU” metric. PSI answers one question and one question only: For how... » read more