kvm_stat

   1 #!/usr/bin/python
   2
   3 import curses
   4 import sys, os, time, optparse
   5
   6 class Stats:
   7     def __init__(self):
   8         self.base = '/sys/kernel/debug/kvm'
   9         self.values = {}
  10         for key in os.listdir(self.base):
  11             self.values[key] = None
  12     def get(self):
  13         for key, oldval in self.values.iteritems():
  14             newval = int(file(self.base + '/' + key).read())
  15             newdelta = None
  16             if oldval is not None:
  17                 newdelta = newval - oldval[0]
  18             self.values[key] = (newval, newdelta)
  19         return self.values
  20
  21 if not os.access('/sys/kernel/debug', os.F_OK):
  22     print 'Please enable CONFIG_DEBUG_FS in your kernel'
  23     sys.exit(1)
  24 if not os.access('/sys/kernel/debug/kvm', os.F_OK):
  25     print "Please mount debugfs ('mount -t debugfs debugfs /sys/kernel/debug')"
  26     print "and ensure the kvm modules are loaded"
  27     sys.exit(1)
  28
  29 stats = Stats()
  30
  31 label_width = 20
  32 number_width = 10
  33
  34 def tui(screen, stats):
  35     curses.use_default_colors()
  36     curses.noecho()
  37     def refresh():
  38         screen.erase()
  39         screen.addstr(0, 0, 'kvm statistics')
  40         row = 2
  41         s = stats.get()
  42         for key in sorted(s.keys()):
  43             if row >= screen.getmaxyx()[0]:
  44                 break
  45             values = s[key]
  46             col = 1
  47             screen.addstr(row, col, key)
  48             col += label_width
  49             screen.addstr(row, col, '%10d' % (values[0],))
  50             col += number_width
  51             if values[1] is not None:
  52                 screen.addstr(row, col, '%8d' % (values[1],))
  53             row += 1
  54         screen.refresh()
  55
  56     while True:
  57         refresh()
  58         curses.halfdelay(10)
  59         try:
  60             c = screen.getkey()
  61             if c == 'q':
  62                 break
  63         except KeyboardInterrupt:
  64             break
  65         except curses.error:
  66             continue
  67
  68 def batch(stats):
  69     s = stats.get()
  70     time.sleep(1)
  71     s = stats.get()
  72     for key in sorted(s.keys()):
  73         values = s[key]
  74         print '%-22s%10d%10d' % (key, values[0], values[1])
  75
  76 options = optparse.OptionParser()
  77 options.add_option('-1', '--once', '--batch',
  78                    action = 'store_true',
  79                    default = False,
  80                    dest = 'once',
  81                    help = 'run in batch mode for one second',
  82                    )
  83 (options, args) = options.parse_args(sys.argv)
  84
  85 if not options.once:
  86     import curses.wrapper
  87     curses.wrapper(tui, stats)
  88 else:
  89     batch(stats)