• Jiri Olsa's avatar
    perf tools: Check maximum frequency rate for record/top · 714647bd
    Jiri Olsa authored
    Adding the check for maximum allowed frequency rate defined in following
    file:
    
      /proc/sys/kernel/perf_event_max_sample_rate
    
    When we cross the maximum value we fail and display detailed error
    message with advise.
    
      $ perf record -F 3000 ls
      Maximum frequency rate (2000) reached.
      Please use -F freq option with lower value or consider
      tweaking /proc/sys/kernel/perf_event_max_sample_rate.
    
    In case user does not specify the frequency and the default value cross
    the maximum, we display warning and set the frequency value to the
    current maximum.
    
      $ perf record ls
      Lowering default frequency rate to 2000.
      Please consider tweaking /proc/sys/kernel/perf_event_max_sample_rate.
    
    Same messages are used for 'perf top'.
    Signed-off-by: default avatarJiri Olsa <jolsa@redhat.com>
    Cc: Adrian Hunter <adrian.hunter@intel.com>
    Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
    Cc: David Ahern <dsahern@gmail.com>
    Cc: Frederic Weisbecker <fweisbec@gmail.com>
    Cc: Ingo Molnar <mingo@elte.hu>
    Cc: Namhyung Kim <namhyung@kernel.org>
    Cc: Paul Mackerras <paulus@samba.org>
    Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Link: http://lkml.kernel.org/r/1383660887-1734-4-git-send-email-jolsa@redhat.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    714647bd
builtin-record.c 24.7 KB