perf tools: Force period term to overload global settings

Currently the command line option settings beats the per event period
settings:

With no global settings, we get per-event configuration:

  $ perf record -e 'cpu/instructions,period=20000/' sleep 1
  $ perf evlist -v
  ... { sample_period, sample_freq }: 20000 ...

With 'c' option period setup, we get 'c' option value:
  $ perf record -e 'cpu/instructions,period=20000/' -c 1000 sleep 1
  $ perf evlist -v
  ... { sample_period, sample_freq }: 1000 ...

This patch makes the per-event settings overload the global 'c' option
setup:

  $ perf record -e 'cpu/instructions,period=20000/' -c 1000 sleep 1
  $ perf evlist -v
  ... { sample_period, sample_freq }: 20000 ...

I think the making the per-event settings to overload any other config
makes more sense than current state. However it breaks the current
'period' term handling, which might cause some noise.. so let's see ;-).

Also fixing parse event tests with the new behaviour.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1438162936-59698-3-git-send-email-kan.liang@intel.com
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-record.txt

@@ -46,7 +46,7 @@ OPTIONS
           /sys/bus/event_sources/devices/<pmu>/format/*
 
 	  There are also some params which are not defined in .../<pmu>/format/*.
-	  These params can be used to set event defaults.
+	  These params can be used to overload default config values per event.
 	  Here is a list of the params.
 	  - 'period': Set event sampling period
 

tools/perf/tests/parse-events.c

@@ -82,8 +82,12 @@ static int test__checkevent_symbolic_name_config(struct perf_evlist *evlist)
 	TEST_ASSERT_VAL("wrong type", PERF_TYPE_HARDWARE == evsel->attr.type);
 	TEST_ASSERT_VAL("wrong config",
 			PERF_COUNT_HW_CPU_CYCLES == evsel->attr.config);
+	/*
+	 * The period value gets configured within perf_evlist__config,
+	 * while this test executes only parse events method.
+	 */
 	TEST_ASSERT_VAL("wrong period",
-			100000 == evsel->attr.sample_period);
+			0 == evsel->attr.sample_period);
 	TEST_ASSERT_VAL("wrong config1",
 			0 == evsel->attr.config1);
 	TEST_ASSERT_VAL("wrong config2",
@@ -406,7 +410,11 @@ static int test__checkevent_pmu(struct perf_evlist *evlist)
 	TEST_ASSERT_VAL("wrong config",    10 == evsel->attr.config);
 	TEST_ASSERT_VAL("wrong config1",    1 == evsel->attr.config1);
 	TEST_ASSERT_VAL("wrong config2",    3 == evsel->attr.config2);
-	TEST_ASSERT_VAL("wrong period",  1000 == evsel->attr.sample_period);
+	/*
+	 * The period value gets configured within perf_evlist__config,
+	 * while this test executes only parse events method.
+	 */
+	TEST_ASSERT_VAL("wrong period",     0 == evsel->attr.sample_period);
 
 	return 0;
 }

tools/perf/util/evsel.c

@@ -594,6 +594,8 @@ static void apply_config_terms(struct perf_event_attr *attr __maybe_unused,
 
 	list_for_each_entry(term, config_terms, list) {
 		switch (term->type) {
+		case PERF_EVSEL__CONFIG_TERM_PERIOD:
+			attr->sample_period = term->val.period;
 		default:
 			break;
 		}

tools/perf/util/evsel.h

@@ -38,6 +38,7 @@ struct cgroup_sel;
  * perf_evsel::config_terms list head.
 */
 enum {
+	PERF_EVSEL__CONFIG_TERM_PERIOD,
 	PERF_EVSEL__CONFIG_TERM_MAX,
 };
 

tools/perf/util/parse-events.c

@@ -596,7 +596,6 @@ do {									   \
 		break;
 	case PARSE_EVENTS__TERM_TYPE_SAMPLE_PERIOD:
 		CHECK_TYPE_VAL(NUM);
-		attr->sample_period = term->val.num;
 		break;
 	case PARSE_EVENTS__TERM_TYPE_BRANCH_SAMPLE_TYPE:
 		/*
@@ -649,6 +648,8 @@ do {								\
 
 	list_for_each_entry(term, head_config, list) {
 		switch (term->type_term) {
+		case PARSE_EVENTS__TERM_TYPE_SAMPLE_PERIOD:
+			ADD_CONFIG_TERM(PERIOD, period, term->val.num);
 		default:
 			break;
 		}