Initial commit of psi-monitor.sh (psi-by-example is too granular)

.gitignore

@@ -2,6 +2,7 @@
 !psi-alerts.sh
 !psi-alerts@.service
 !psi-monitor.service
+!psi-monitor.sh
 !psi-by-example
 !.gitignore
 !CONFIGURE.md

psi-monitor.sh

@@ -0,0 +1,62 @@
+#!/usr/bin/env zsh
+#
+# Pressure Stall Information monitor
+#
+#    Copyright © 2023 Trey Blancher $(base64 -d <<< dHJleUBibGFuY2hlci5uZXQK)
+#
+#    This program is free software: you can redistribute it and/or modify it
+#    under the terms of the GNU General Public License as published by the Free
+#    Software Foundation, either version 3 of the License, or (at your option)
+#    any later version.
+#
+#    This program is distributed in the hope that it will be useful, but
+#    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+#    or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+#    for more details.
+#
+#    You should have received a copy of the GNU General Public License along
+#    with this program.  If not, see <https://www.gnu.org/licenses/>.
+#
+#    Submodules may be distributed under a separate software license;  see the
+#    LICENSE file within each submodule.
+# 
+# This script monitors the three pressure stall information files
+# /proc/pressure{cpu,io,memory} and reports if any resource is above threshold
+# for the "some" values.  It takes an optional single argument, the threshold at
+# which to alert.  If this is not supplied, it defaults to a threshold of 30.0 
+# percent.
+#
+
+local cpu="/proc/pressure/cpu"
+local cpu_ctr=0
+local io="/proc/pressure/io"
+local io_ctr=0
+local mem="/proc/pressure/memory"
+local mem_ctr=0
+local threshold=30.0
+
+if [[ -n "${1}" ]]; then
+    threshold=${1}
+fi
+
+# main loop
+while true; do
+    local cpu_pct=$(grep 'some' ${cpu} | awk '{print $2}' | awk -F'=' '{print $2}')    
+    local io_pct=$(grep 'some' ${io} | awk '{print $2}' | awk -F'=' '{print $2}')    
+    local mem_pct=$(grep 'some' ${mem} | awk '{print $2}' | awk -F'=' '{print $2}')    
+    
+    if (( cpu_pct > threshold )); then
+        cpu_ctr=$(( ${cpu_ctr} + 1 ))
+        printf "CPU PSI event %d triggered.\n" ${cpu_ctr}
+    fi
+    if (( io_pct > threshold )); then
+        io_ctr=$(( ${io_ctr} + 1 ))
+        printf "IO PSI event %d triggered.\n" ${io_ctr}
+    fi
+    if (( mem_pct > threshold )); then
+        mem_ctr=$(( ${mem_ctr} + 1 ))
+        printf "MEM PSI event %d triggered.\n" ${mem_ctr}
+    fi
+
+    sleep 10
+done