perf tools: Check maximum frequency rate for record/top

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>

1 files changed, 1 insertions, 14 deletions

diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 21897f0ffcd3..9acca8856ccb 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -1209,20 +1209,7 @@ int cmd_top(int argc, const char **argv, const char *prefix __maybe_unused)
         if (top.delay_secs < 1)
                 top.delay_secs = 1;
 
-        if (opts->user_interval != ULLONG_MAX)
-                opts->default_interval = opts->user_interval;
-        if (opts->user_freq != UINT_MAX)
-                opts->freq = opts->user_freq;
-
-        /*
-         * User specified count overrides default frequency.
-         */
-        if (opts->default_interval)
-                opts->freq = 0;
-        else if (opts->freq) {
-                opts->default_interval = opts->freq;
-        } else {
-                ui__error("frequency and count are zero, aborting\n");
+        if (perf_record_opts__config(opts)) {
                 status = -EINVAL;
                 goto out_delete_maps;
         }