1. 07 Jan, 2016 1 commit
    • Arnaldo Carvalho de Melo's avatar
      perf tests: No need to set attr.sample_freq in the perf time to TSC test · 4f4ba0e6
      Arnaldo Carvalho de Melo authored
      We were asking for a 4kHz sample_freq, making the test fail needlessly
      when the system reduced /proc/sys/kernel/perf_event_max_sample_rate
      below that.
      
      In this test we only look at the PERF_SAMPLE_TIME fields in PERF_RECORD_
      meta events, no need to set sample_freq.
      
      Thanks to Namhyung for suggesting that max_sample_rate could be the
      reason for the test failure, seeing the 'perf test -vv' output I sent.
      
      Before:
      
        # echo 1000 > /proc/sys/kernel/perf_event_max_sample_rate
        # perf test TSC
        45: Test converting perf time to TSC   : FAILED!
      
      After:
      
        # perf test TSC
        45: Test converting perf time to TSC   : Ok
        # cat /proc/sys/kernel/perf_event_max_sample_rate
        1000
      
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Wang Nan <wangnan0@huawei.com>
      Link: http://lkml.kernel.org/n/tip-lcob05qhawkuvsyuu9g1fld5@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      4f4ba0e6
  2. 06 Jan, 2016 39 commits