kvm_stat

   1 #!/usr/bin/python
   2
   3 import curses
   4 import sys, os, time, optparse
   5
   6 class Stats:
   7     def __init__(self, fields = None):
   8         def wanted(key):
   9             import re
  10             if not fields:
  11                 return True
  12             return re.match(fields, key) != None
  13         self.base = '/sys/kernel/debug/kvm'
  14         self.values = {}
  15         for key in os.listdir(self.base):
  16             if wanted(key):
  17                 self.values[key] = None
  18     def get(self):
  19         for key, oldval in self.values.iteritems():
  20             newval = int(file(self.base + '/' + key).read())
  21             newdelta = None
  22             if oldval is not None:
  23                 newdelta = newval - oldval[0]
  24             self.values[key] = (newval, newdelta)
  25         return self.values
  26
  27 if not os.access('/sys/kernel/debug', os.F_OK):
  28     print 'Please enable CONFIG_DEBUG_FS in your kernel'
  29     sys.exit(1)
  30 if not os.access('/sys/kernel/debug/kvm', os.F_OK):
  31     print "Please mount debugfs ('mount -t debugfs debugfs /sys/kernel/debug')"
  32     print "and ensure the kvm modules are loaded"
  33     sys.exit(1)
  34
  35 label_width = 20
  36 number_width = 10
  37
  38 def tui(screen, stats):
  39     curses.use_default_colors()
  40     curses.noecho()
  41     def refresh():
  42         screen.erase()
  43         screen.addstr(0, 0, 'kvm statistics')
  44         row = 2
  45         s = stats.get()
  46         for key in sorted(s.keys()):
  47             if row >= screen.getmaxyx()[0]:
  48                 break
  49             values = s[key]
  50             col = 1
  51             screen.addstr(row, col, key)
  52             col += label_width
  53             screen.addstr(row, col, '%10d' % (values[0],))
  54             col += number_width
  55             if values[1] is not None:
  56                 screen.addstr(row, col, '%8d' % (values[1],))
  57             row += 1
  58         screen.refresh()
  59
  60     while True:
  61         refresh()
  62         curses.halfdelay(10)
  63         try:
  64             c = screen.getkey()
  65             if c == 'q':
  66                 break
  67         except KeyboardInterrupt:
  68             break
  69         except curses.error:
  70             continue
  71
  72 def batch(stats):
  73     s = stats.get()
  74     time.sleep(1)
  75     s = stats.get()
  76     for key in sorted(s.keys()):
  77         values = s[key]
  78         print '%-22s%10d%10d' % (key, values[0], values[1])
  79
  80 def log(stats):
  81     keys = sorted(stats.get().iterkeys())
  82     def banner():
  83         for k in keys:
  84             print '%10s' % k[0:9],
  85         print
  86     def statline():
  87         s = stats.get()
  88         for k in keys:
  89             print ' %9d' % s[k][1],
  90         print
  91     line = 0
  92     banner_repeat = 20
  93     while True:
  94         time.sleep(1)
  95         if line % banner_repeat == 0:
  96             banner()
  97         statline()
  98         line += 1
  99
 100 options = optparse.OptionParser()
 101 options.add_option('-1', '--once', '--batch',
 102                    action = 'store_true',
 103                    default = False,
 104                    dest = 'once',
 105                    help = 'run in batch mode for one second',
 106                    )
 107 options.add_option('-l', '--log',
 108                    action = 'store_true',
 109                    default = False,
 110                    dest = 'log',
 111                    help = 'run in logging mode (like vmstat)',
 112                    )
 113 options.add_option('-f', '--fields',
 114                    action = 'store',
 115                    default = None,
 116                    dest = 'fields',
 117                    help = 'fields to display (regex)',
 118                    )
 119 (options, args) = options.parse_args(sys.argv)
 120
 121 stats = Stats(fields = options.fields)
 122
 123 if options.log:
 124     log(stats)
 125 elif not options.once:
 126     import curses.wrapper
 127     curses.wrapper(tui, stats)
 128 else:
 129     batch(stats)