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      1 # Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
      2 # Use of this source code is governed by a BSD-style license that can be
      3 # found in the LICENSE file.
      4 import os, re, subprocess
      5 from autotest_lib.client.bin import test
      6 from autotest_lib.client.common_lib import error
      7 
      8 
      9 class platform_Perf(test.test):
     10     """
     11     Gathers perf data and makes sure it is well-formed.
     12     """
     13     version = 1
     14 
     15 
     16     def run_once(self):
     17         """
     18         Collect a perf data profile and check the detailed perf report.
     19         """
     20         keyvals = {}
     21         num_errors = 0
     22 
     23         try:
     24             # Create temporary file and get its name. Then close it.
     25             perf_file_path = os.tempnam()
     26 
     27             # Perf command for recording a profile.
     28             perf_record_args = [ 'perf', 'record', '-a', '-o', perf_file_path,
     29                                  '--', 'sleep', '2']
     30             # Perf command for getting a detailed report.
     31             perf_report_args = [ 'perf', 'report', '-D', '-i', perf_file_path ]
     32 
     33             try:
     34                 subprocess.check_output(perf_record_args,
     35                                         stderr=subprocess.STDOUT)
     36             except subprocess.CalledProcessError as cmd_error:
     37                 raise error.TestFail("Running command [%s] failed: %s" %
     38                                      (' '.join(perf_record_args),
     39                                       cmd_error.output))
     40 
     41             # Make sure the file still exists.
     42             if not os.path.isfile(perf_file_path):
     43                 raise error.TestFail('Could not find perf output file: ' +
     44                                      perf_file_path)
     45 
     46             # Get detailed perf data view and extract the line containing the
     47             # kernel MMAP summary.
     48             result = None
     49             p = subprocess.Popen(perf_report_args, stdout=subprocess.PIPE)
     50             for line in p.stdout:
     51                 if 'PERF_RECORD_MMAP' in line and 'kallsyms' in line:
     52                     result = line
     53                     break;
     54 
     55             # Read the rest of output to EOF.
     56             for _ in p.stdout:
     57                 pass
     58             p.wait();
     59 
     60         finally:
     61             # Delete the perf data file.
     62             try:
     63                 os.remove(perf_file_path)
     64             except OSError as e:
     65                 if e.errno != errno.ENONENT: raise
     66 
     67         if result is None:
     68             raise error.TestFail('Could not find kernel mapping in perf '
     69                                  'report.')
     70         # Get the kernel mapping values.
     71         result = result.split(':')[2]
     72         start, length, pgoff = re.sub(r'[][()@]', ' ', result).strip().split()
     73 
     74         # Write keyvals.
     75         keyvals = {}
     76         keyvals['start'] = start
     77         keyvals['length'] = length
     78         keyvals['pgoff'] = pgoff
     79         self.write_perf_keyval(keyvals)
     80 
     81         # Make sure that the kernel mapping values follow an expected pattern,
     82         #
     83         # Expect one of two patterns:
     84         # (1) start == pgoff, e.g.:
     85         #   start=0x80008200
     86         #   pgoff=0x80008200
     87         #   len  =0xfffffff7ff7dff
     88         # (2) start < pgoff < start + len, e.g.:
     89         #   start=0x3bc00000
     90         #   pgoff=0xffffffffbcc00198
     91         #   len  =0xffffffff843fffff
     92         start = int(start, 0)
     93         length = int(length, 0)
     94         pgoff = int(pgoff, 0)
     95         if not (start == pgoff or start < pgoff < start + length):
     96             raise error.TestFail('Improper kernel mapping values!')
     97