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perf tools: Check maximum frequency rate for record/top

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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>
This commit is contained in:
Jiri Olsa
2013-11-05 15:14:47 +01:00
committed by Arnaldo Carvalho de Melo
parent a986241854
commit 714647bdc5
4 changed files with 74 additions and 28 deletions
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15
tools/perf/builtin-record.c
View File

@@ -958,20 +958,7 @@ int cmd_record(int argc, const char **argv, const char *prefix __maybe_unused)
if (perf_evlist__create_maps(evsel_list, &rec->opts.target) < 0)
usage_with_options(record_usage, record_options);
if (rec->opts.user_interval != ULLONG_MAX)
rec->opts.default_interval = rec->opts.user_interval;
if (rec->opts.user_freq != UINT_MAX)
rec->opts.freq = rec->opts.user_freq;
/*
* User specified count overrides default frequency.
*/
if (rec->opts.default_interval)
rec->opts.freq = 0;
else if (rec->opts.freq) {
rec->opts.default_interval = rec->opts.freq;
} else {
ui__error("frequency and count are zero, aborting\n");
if (perf_record_opts__config(&rec->opts)) {
err = -EINVAL;
goto out_free_fd;
}