android_kernel_motorola_sm6225/Documentation/accounting
Suren Baghdasaryan 617a4ba0ec FROMLIST: psi: introduce psi monitor
Psi monitor aims to provide a low-latency short-term pressure
detection mechanism configurable by users. It allows users to
monitor psi metrics growth and trigger events whenever a metric
raises above user-defined threshold within user-defined time window.

Time window and threshold are both expressed in usecs. Multiple psi
resources with different thresholds and window sizes can be monitored
concurrently.

Psi monitors activate when system enters stall state for the monitored
psi metric and deactivate upon exit from the stall state. While system
is in the stall state psi signal growth is monitored at a rate of 10 times
per tracking window. Min window size is 500ms, therefore the min monitoring
interval is 50ms. Max window size is 10s with monitoring interval of 1s.

When activated psi monitor stays active for at least the duration of one
tracking window to avoid repeated activations/deactivations when psi
signal is bouncing.

Notifications to the users are rate-limited to one per tracking window.

Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>

(not upstream yet, latest version published at: https://lore.kernel.org/patchwork/patch/1052418/)

Bug: 127712811
Bug: 129157727
Test: lmkd in PSI mode
Change-Id: I860049d32420485346ad545c4650f990fe0c08e3
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-03-22 23:07:14 +00:00
..
cgroupstats.txt Documentation: update cgroupfs mount point 2011-06-15 21:52:50 -07:00
delay-accounting.txt tools: move accounting tool from Documentation 2016-09-23 13:07:15 -06:00
psi.txt FROMLIST: psi: introduce psi monitor 2019-03-22 23:07:14 +00:00
taskstats-struct.txt Documentation cleanup: trivial misspelling, punctuation, and grammar corrections. 2008-07-26 12:00:06 -07:00
taskstats.txt Fix typos in /Documentation : 'U-Z' 2006-11-30 04:58:40 +01:00