perf_counter tools: Clean up builtin-stat.c's do_perfstat()

[ Impact: cleanup ]

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Kacur <jkacur@redhat.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

Documentation/perf_counter/builtin-stat.c

@@ -109,56 +109,33 @@ static void create_perfstat_counter(int counter)
 	}
 }
 
-static int do_perfstat(int argc, const char **argv)
+/*
+ * Does the counter have nsecs as a unit?
+ */
+static inline int nsec_counter(int counter)
 {
-	unsigned long long t0, t1;
-	int counter;
-	ssize_t res;
-	int status;
-	int pid;
-
-	if (!system_wide)
-		nr_cpus = 1;
+	if (event_id[counter] == EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CPU_CLOCK))
+		return 1;
+	if (event_id[counter] == EID(PERF_TYPE_SOFTWARE, PERF_COUNT_TASK_CLOCK))
+		return 1;
 
-	for (counter = 0; counter < nr_counters; counter++)
-		create_perfstat_counter(counter);
+	return 0;
+}
 
-	/*
-	 * Enable counters and exec the command:
+/*
+ * Print out the results of a single counter:
  */
-	t0 = rdclock();
-	prctl(PR_TASK_PERF_COUNTERS_ENABLE);
-
-	if ((pid = fork()) < 0)
-		perror("failed to fork");
-	if (!pid) {
-		if (execvp(argv[0], (char **)argv)) {
-			perror(argv[0]);
-			exit(-1);
-		}
-	}
-	while (wait(&status) >= 0)
-		;
-	prctl(PR_TASK_PERF_COUNTERS_DISABLE);
-	t1 = rdclock();
-
-	fflush(stdout);
-
-	fprintf(stderr, "\n");
-	fprintf(stderr, " Performance counter stats for \'%s\':\n",
-		argv[0]);
-	fprintf(stderr, "\n");
-
-	for (counter = 0; counter < nr_counters; counter++) {
-		int cpu, nv;
+static void print_counter(int counter)
+{
 	__u64 count[3], single_count[3];
+	ssize_t res;
+	int cpu, nv;
 	int scaled;
 
 	count[0] = count[1] = count[2] = 0;
 	nv = scale ? 3 : 1;
 	for (cpu = 0; cpu < nr_cpus; cpu ++) {
-			res = read(fd[cpu][counter],
-				   single_count, nv * sizeof(__u64));
+		res = read(fd[cpu][counter], single_count, nv * sizeof(__u64));
 		assert(res == nv * sizeof(__u64));
 
 		count[0] += single_count[0];
@@ -173,7 +150,7 @@ static int do_perfstat(int argc, const char **argv)
 		if (count[2] == 0) {
 			fprintf(stderr, " %14s  %-20s\n",
 				"<not counted>", event_name(counter));
-				continue;
+			return;
 		}
 		if (count[2] < count[1]) {
 			scaled = 1;
@@ -182,9 +159,7 @@ static int do_perfstat(int argc, const char **argv)
 		}
 	}
 
-		if (event_id[counter] == EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CPU_CLOCK) ||
-		    event_id[counter] == EID(PERF_TYPE_SOFTWARE, PERF_COUNT_TASK_CLOCK)) {
-
+	if (nsec_counter(counter)) {
 		double msecs = (double)count[0] / 1000000;
 
 		fprintf(stderr, " %14.6f  %-20s (msecs)",
@@ -197,7 +172,51 @@ static int do_perfstat(int argc, const char **argv)
 		fprintf(stderr, "  (scaled from %.2f%%)",
 			(double) count[2] / count[1] * 100);
 	fprintf(stderr, "\n");
+}
+
+static int do_perfstat(int argc, const char **argv)
+{
+	unsigned long long t0, t1;
+	int counter;
+	int status;
+	int pid;
+
+	if (!system_wide)
+		nr_cpus = 1;
+
+	for (counter = 0; counter < nr_counters; counter++)
+		create_perfstat_counter(counter);
+
+	/*
+	 * Enable counters and exec the command:
+	 */
+	t0 = rdclock();
+	prctl(PR_TASK_PERF_COUNTERS_ENABLE);
+
+	if ((pid = fork()) < 0)
+		perror("failed to fork");
+	if (!pid) {
+		if (execvp(argv[0], (char **)argv)) {
+			perror(argv[0]);
+			exit(-1);
 		}
+	}
+	while (wait(&status) >= 0)
+		;
+	prctl(PR_TASK_PERF_COUNTERS_DISABLE);
+	t1 = rdclock();
+
+	fflush(stdout);
+
+	fprintf(stderr, "\n");
+	fprintf(stderr, " Performance counter stats for \'%s\':\n",
+		argv[0]);
+	fprintf(stderr, "\n");
+
+	for (counter = 0; counter < nr_counters; counter++)
+		print_counter(counter);
+
+
 	fprintf(stderr, "\n");
 	fprintf(stderr, " Wall-clock time elapsed: %12.6f msecs\n",
 			(double)(t1-t0)/1e6);
@@ -212,7 +231,6 @@ static void skip_signal(int signo)
 
 static const char * const stat_usage[] = {
 	"perf stat [<options>] <command>",
-	"perf stat [<options>] -- <command> [<options>]",
 	NULL
 };