perf tools: Add stat config event synthesize function

Introduce the perf_event__synthesize_stat_config to synthesize a 'struct
perf_stat_config'.

Storing the stat config in the form of tag-value pairs will, I believe,
sort out future version extensibility issues.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Kan Liang <kan.liang@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1445784728-21732-13-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/Build

@@ -35,6 +35,7 @@ perf-y += llvm.o llvm-src-base.o llvm-src-kbuild.o llvm-src-prologue.o
 perf-y += bpf.o
 perf-y += topology.o
 perf-y += cpumap.o
+perf-y += stat.o
 
 $(OUTPUT)tests/llvm-src-base.c: tests/bpf-script-example.c tests/Build
 	$(call rule_mkdir)

tools/perf/tests/builtin-test.c

@@ -187,6 +187,10 @@ static struct test generic_tests[] = {
 		.desc = "Test cpu map synthesize",
 		.func = test__cpu_map_synthesize,
 	},
+	{
+		.desc = "Test stat config synthesize",
+		.func = test__synthesize_stat_config,
+	},
 	{
 		.func = NULL,
 	},

tools/perf/tests/stat.c

@@ -0,0 +1,53 @@
+#include <linux/compiler.h>
+#include "event.h"
+#include "tests.h"
+#include "stat.h"
+#include "debug.h"
+
+static bool has_term(struct stat_config_event *config,
+		     u64 tag, u64 val)
+{
+	unsigned i;
+
+	for (i = 0; i < config->nr; i++) {
+		if ((config->data[i].tag == tag) &&
+		    (config->data[i].val == val))
+			return true;
+	}
+
+	return false;
+}
+
+static int process_event(struct perf_tool *tool __maybe_unused,
+			 union perf_event *event,
+			 struct perf_sample *sample __maybe_unused,
+			 struct machine *machine __maybe_unused)
+{
+	struct stat_config_event *config = &event->stat_config;
+
+#define HAS(term, val) \
+	has_term(config, PERF_STAT_CONFIG_TERM__##term, val)
+
+	TEST_ASSERT_VAL("wrong nr",        config->nr == PERF_STAT_CONFIG_TERM__MAX);
+	TEST_ASSERT_VAL("wrong aggr_mode", HAS(AGGR_MODE, AGGR_CORE));
+	TEST_ASSERT_VAL("wrong scale",     HAS(SCALE, 1));
+	TEST_ASSERT_VAL("wrong interval",  HAS(INTERVAL, 1));
+
+#undef HAS
+
+	return 0;
+}
+
+int test__synthesize_stat_config(int subtest __maybe_unused)
+{
+	struct perf_stat_config stat_config = {
+		.aggr_mode	= AGGR_CORE,
+		.scale		= 1,
+		.interval	= 1,
+	};
+
+	TEST_ASSERT_VAL("failed to synthesize stat_config",
+		!perf_event__synthesize_stat_config(NULL, &stat_config, process_event, NULL));
+
+	return 0;
+}

tools/perf/tests/tests.h

@@ -81,6 +81,7 @@ int test__bpf_subtest_get_nr(void);
 int test_session_topology(int subtest);
 int test__thread_map_synthesize(int subtest);
 int test__cpu_map_synthesize(int subtest);
+int test__synthesize_stat_config(int subtest);
 
 #if defined(__arm__) || defined(__aarch64__)
 #ifdef HAVE_DWARF_UNWIND_SUPPORT

tools/perf/util/event.c

@@ -10,6 +10,8 @@
 #include "thread.h"
 #include "thread_map.h"
 #include "symbol/kallsyms.h"
+#include "asm/bug.h"
+#include "stat.h"
 
 static const char *perf_event__names[] = {
 	[0]					= "TOTAL",
@@ -869,6 +871,44 @@ int perf_event__synthesize_cpu_map(struct perf_tool *tool,
 	return err;
 }
 
+int perf_event__synthesize_stat_config(struct perf_tool *tool,
+				       struct perf_stat_config *config,
+				       perf_event__handler_t process,
+				       struct machine *machine)
+{
+	struct stat_config_event *event;
+	int size, i = 0, err;
+
+	size  = sizeof(*event);
+	size += (PERF_STAT_CONFIG_TERM__MAX * sizeof(event->data[0]));
+
+	event = zalloc(size);
+	if (!event)
+		return -ENOMEM;
+
+	event->header.type = PERF_RECORD_STAT_CONFIG;
+	event->header.size = size;
+	event->nr          = PERF_STAT_CONFIG_TERM__MAX;
+
+#define ADD(__term, __val)					\
+	event->data[i].tag = PERF_STAT_CONFIG_TERM__##__term;	\
+	event->data[i].val = __val;				\
+	i++;
+
+	ADD(AGGR_MODE,	config->aggr_mode)
+	ADD(INTERVAL,	config->interval)
+	ADD(SCALE,	config->scale)
+
+	WARN_ONCE(i != PERF_STAT_CONFIG_TERM__MAX,
+		  "stat config terms unbalanced\n");
+#undef ADD
+
+	err = process(tool, (union perf_event *) event, NULL, machine);
+
+	free(event);
+	return err;
+}
+
 size_t perf_event__fprintf_comm(union perf_event *event, FILE *fp)
 {
 	const char *s;

tools/perf/util/event.h

@@ -446,6 +446,7 @@ void perf_event__print_totals(void);
 struct perf_tool;
 struct thread_map;
 struct cpu_map;
+struct perf_stat_config;
 
 typedef int (*perf_event__handler_t)(struct perf_tool *tool,
 				     union perf_event *event,
@@ -472,6 +473,10 @@ int perf_event__synthesize_threads(struct perf_tool *tool,
 int perf_event__synthesize_kernel_mmap(struct perf_tool *tool,
 				       perf_event__handler_t process,
 				       struct machine *machine);
+int perf_event__synthesize_stat_config(struct perf_tool *tool,
+				       struct perf_stat_config *config,
+				       perf_event__handler_t process,
+				       struct machine *machine);
 
 int perf_event__synthesize_modules(struct perf_tool *tool,
 				   perf_event__handler_t process,