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      1 #!/usr/bin/python
      2 
      3 """
      4 python-libpfm4 provides python bindings to the libpfm4
      5 library and the perf_event kernel subsystem. This
      6 script builds on them to provide a *stat like interface
      7 to CPU performance counters.
      8 
      9 Run as: ./cpistat -c cpulist -e eventlist
     10 
     11 Depends on libpfm4: http://perfmon2.sf.net/
     12 
     13 git://perfmon2.git.sourceforge.net/gitroot/perfmon2/libpfm4
     14 """
     15 
     16 import sys, os, optparse, time, struct, perfmon
     17 
     18 if __name__ == '__main__':
     19     parser = optparse.OptionParser()
     20     parser.add_option('-e', '--events', help='Events to use',
     21                        action='store', dest='events')
     22     parser.add_option('-c', '--cpulist', help='CPUs to monitor',
     23                        action='store', dest='cpulist')
     24     parser.set_defaults(events='PERF_COUNT_HW_CPU_CYCLES,' +
     25                                'PERF_COUNT_HW_INSTRUCTIONS')
     26     (options, args) = parser.parse_args()
     27 
     28     show_per_cpu = False
     29     if not options.cpulist:
     30         ncpus = os.sysconf('SC_NPROCESSORS_ONLN')
     31         cpus = range(0, ncpus)
     32     else:
     33         cpus = options.cpulist.split(',')
     34         cpus = [ int(c) for c in cpus ]
     35         show_per_cpu = True
     36 
     37     if options.events:
     38         events = options.events.split(',')
     39     else:
     40         raise ValueError('You need to specify events to monitor')
     41 
     42     s = perfmon.SystemWideSession(cpus, events)
     43 
     44     s.start()
     45     # Measuring loop
     46     interval = 1
     47     iters = -1
     48     infinite = True
     49     if len(args) == 2:
     50         interval = int(args[0])
     51         iters = int(args[1])
     52         infinite = False
     53 
     54     delta = {}
     55     last = {}
     56     sum = {}
     57     for e in events:
     58         delta[e] = {}
     59         last[e] = {}
     60         sum[e] = {}
     61         for c in cpus:
     62             delta[e][c] = 0
     63             last[e][c] = 0
     64 
     65     while infinite or iters:
     66         for i in range(0, len(events)):
     67           e = events[i]
     68           sum[e] = 0
     69           for c in cpus:
     70               count = struct.unpack('L', s.read(c, i))[0]
     71               delta[e][c] = count - last[e][c]
     72               last[e][c] = count
     73               if show_per_cpu:
     74                   print '''CPU%d: %s\t%lu''' % (c, e, delta[e][c])
     75               sum[e] += delta[e][c]
     76 
     77         cycles = sum['PERF_COUNT_HW_CPU_CYCLES']
     78         instructions = sum['PERF_COUNT_HW_INSTRUCTIONS']
     79         CPI = cycles * 1.0/instructions
     80         print ('cycles: %12lu, instructions: %12lu, CPI: %2.4f'
     81                % (cycles, instructions, CPI))
     82         sys.stdout.flush()
     83         time.sleep(interval)
     84         iters = iters - 1
     85