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: Jiri 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.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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