contrib/statusd/statusd_cpustat.lua

   1 -- Authors: Tibor Csögör <tibi@tiborius.net>
   2 -- License: Public domain
   3 -- Last Changed: 2007-03-10
   4 --
   5 -- $Id: statusd_cpustat.lua 80 2007-03-10 00:16:09Z tibi $
   6
   7 -- statusd_cpustat.lua -- CPU monitor for Ion3's statusbar
   8
   9 -- version : 0.3
  10 -- date    : 2007-03-10
  11 -- author  : Tibor Csögör <tibi@tiborius.net>
  12
  13 -- Shows the CPU utilization of the system similiar to top(1).
  14 -- This script depends on the /proc filesystem and thus only works on Linux.
  15 -- Tested with kernel 2.6.16.
  16
  17 -- Configuration:
  18 -- The following placeholders (with a "cpustat_" prefix) can be used in the
  19 -- statusbar template: `user', `nice', `idle', `system', `iowait', `irq',
  20 -- `softirq' and `steal'.  In addition, `system_adj' sums up the last 5 fields.
  21 -- For a compact output simply use the `cpustat' placeholder.
  22
  23 -- This software is in the public domain.
  24
  25 --------------------------------------------------------------------------------
  26
  27
  28 local defaults = {
  29    update_interval = 1000, -- 1 second
  30 }
  31
  32 local settings = table.join(statusd.get_config("cpustat"), defaults)
  33
  34 local last_stat, current_stat
  35 local last_uptime, current_uptime = 0, 0
  36 local first_run = true
  37
  38 function math.round(number, precision)
  39    local m = 10^(precision or 0)
  40    return math.floor((number*m)+(1/2)) / m
  41 end
  42
  43 -- this function reads stats from /proc/stat and /proc/uptime and calculates the
  44 -- CPU time used in the measurement interval
  45 local function get_cpustat()
  46    local f1, f2, s, s2
  47    f1 = io.open('/proc/stat', 'r')
  48    f2 = io.open('/proc/uptime', 'r')
  49    if ((f1 == nil ) or (f2 == nil)) then return nil end
  50    s = f1:read("*l")
  51    s2 = f2:read("*l")
  52    f1:close()
  53    f2:close()
  54
  55    last_uptime = current_uptime
  56    local tmp, tmp, up1, up2
  57    tmp, tmp, up1, up2 = string.find(s2, "(%d+)\.(%d+)%s%d")
  58    current_uptime = tonumber(up1 .. up2)
  59    local uptime_interv = current_uptime - last_uptime
  60
  61    local t = {}
  62    for tmp in string.gfind(s, "%s+(%d+)") do
  63       table.insert(t, tonumber(tmp))
  64    end
  65
  66    last_stat = current_stat
  67    current_stat = t
  68    if (first_run) then
  69       last_stat = t
  70       first_run = false
  71    end
  72
  73    local c = {}
  74    for i = 1, #(t) do
  75       table.insert(c, math.round(((current_stat[i] - last_stat[i])
  76                                   / uptime_interv) * 100))
  77    end
  78
  79    -- adjusted system CPU time (= system + iowait + irq + softirq + steal)
  80    table.insert(c, math.round((((current_stat[3] - last_stat[3]) +
  81                                 (current_stat[5] - last_stat[5]) +
  82                                 (current_stat[6] - last_stat[6]) +
  83                                 (current_stat[7] - last_stat[7]) +
  84                                 (current_stat[8] - last_stat[8]))
  85                                   / uptime_interv) * 100))
  86    return c
  87 end
  88
  89 local cpustat_timer = statusd.create_timer()
  90
  91 local function update_cpustat()
  92    local t = get_cpustat()
  93    if (t == nil) then return nil end
  94    statusd.inform("cpustat_user", t[1] .. "%")
  95    statusd.inform("cpustat_nice", t[2] .. "%")
  96    statusd.inform("cpustat_system", t[3] .. "%")
  97    statusd.inform("cpustat_system_adj", t[9] .. "%")
  98    statusd.inform("cpustat_idle", t[4] .. "%")
  99    statusd.inform("cpustat_iowait", t[5] .. "%")
 100    statusd.inform("cpustat_irq", t[6] .. "%")
 101    statusd.inform("cpustat_softirq", t[7] .. "%")
 102    statusd.inform("cpustat_steal", t[8] .. "%")
 103    statusd.inform("cpustat", string.format("%3d%% us,%3d%% sy,%3d%% ni",
 104                                            t[1], t[9], t[2]))
 105    cpustat_timer:set(settings.update_interval, update_cpustat)
 106 end
 107
 108 update_cpustat()
 109
 110 -- EOF