hesela.devPressure Stall Information (PSI)
Pressure Stall Information measures time during which tasks are stalled on CPU, memory or I/O resources.
For I/O pressure, some tracks intervals with at least one stalled task; full tracks intervals when all non-idle tasks are stalled simultaneously. Each line's total accumulates stall time in microseconds; avg10, avg60 and avg300 report percentage trends over their respective windows. [1]
/proc/pressure/io describes system scope; cgroup v2 io.pressure describes a group. full is a subset of some, so their totals must not be added. Neither is a device-busy percentage, request-latency percentile or sum of individual request latencies. [1]
Relations
Limitations
- System-level CPU full is undefined and reported as zero in the documented interface. [1]
Citations
Sources & caveats
- Source synthesis from Linux 6.12 documentation; no new host measurements or universal performance guarantee.