[PATCH 4/8] perf, tools, stat: Implement CSV metrics output

[Andi Kleen]

From: Andi Kleen <ak@xxxxxxxxxxxxxxx>

Now support CSV output for metrics. With the new output callbacks
this is relatively straight forward by creating new callbacks.

The new line callback needs to know the number of fields to skip them
correctly

Example output before:

% perf stat -x, true
0.200687,,task-clock,200687,100.00
0,,context-switches,200687,100.00
0,,cpu-migrations,200687,100.00
40,,page-faults,200687,100.00
730871,,cycles,203601,100.00
551056,,stalled-cycles-frontend,203601,100.00
<not supported>,,stalled-cycles-backend,0,100.00
385523,,instructions,203601,100.00
78028,,branches,203601,100.00
3946,,branch-misses,203601,100.00

After:

% perf stat -x, true
0.341119,,task-clock,0.461,CPUs utilized,0.00%,324342,100.00
0,,context-switches,0.000,K/sec,0.00%,324342,100.00
0,,cpu-migrations,0.000,K/sec,0.00%,324342,100.00
41,,page-faults,0.126,M/sec,0.00%,324342,100.00
674068,,cycles,2.078,GHz,0.00%,330887,100.00
508189,,stalled-cycles-frontend,82.31,frontend cycles idle,0.00%,330887,100.00
<not supported>,,stalled-cycles-backend,,,0.00%,0,100.00
374932,,instructions,0.61,insn per cycle
,,,1.20,stalled cycles per insn,0.00%,330887,100.00
76540,,branches,235.985,M/sec,0.00%,330887,100.00
3091,,branch-misses,4.09,of all branches,0.00%,330887,100.00

Two new fields are added: metric value and metric name before
the running/enabled fields.

v2: Split out function argument changes
v3: Reenable metrics for real.
v4: Fix wrong hunk from refactoring.
v5: Remove extra "noise" printing (Jiri), but add it to the not counted case.
Print empty metrics for not counted.
v6: Avoid outputting metric on empty format.
Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
---
 tools/perf/builtin-stat.c | 62 +++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 60 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index bfb6e07..86caf70 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -739,6 +739,8 @@ struct outstate {
 	FILE *fh;
 	bool newline;
 	const char *prefix;
+	int  nfields;
+	u64  run, ena;
 };
 
 #define METRIC_LEN  35
@@ -789,6 +791,43 @@ static void print_metric_std(void *ctx, const char *color, const char *fmt,
 	fprintf(out, " %-*s", METRIC_LEN - n - 1, unit);
 }
 
+static void new_line_csv(void *ctx)
+{
+	struct outstate *os = ctx;
+	int i;
+
+	fputc('\n', os->fh);
+	if (os->prefix)
+		fprintf(os->fh, "%s%s", os->prefix, csv_sep);
+	for (i = 0; i < os->nfields; i++)
+		fputs(csv_sep, os->fh);
+}
+
+static void print_metric_csv(void *ctx,
+			     const char *color __maybe_unused,
+			     const char *fmt, const char *unit, double val)
+{
+	struct outstate *os = ctx;
+	FILE *out = os->fh;
+	char buf[64], *vals, *ends;
+
+	if (unit == NULL || fmt == NULL) {
+		fprintf(out, "%s%s%s%s", csv_sep, csv_sep, csv_sep, csv_sep);
+		return;
+	}
+	snprintf(buf, sizeof(buf), fmt, val);
+	vals = buf;
+	while (isspace(*vals))
+		vals++;
+	ends = vals;
+	while (isdigit(*ends) || *ends == '.')
+		ends++;
+	*ends = 0;
+	while (isspace(*unit))
+		unit++;
+	fprintf(out, "%s%s%s%s", csv_sep, vals, csv_sep, unit);
+}
+
 static void nsec_printout(int id, int nr, struct perf_evsel *evsel, double avg)
 {
 	FILE *output = stat_config.output;
@@ -860,6 +899,24 @@ static void printout(int id, int nr, struct perf_evsel *counter, double uval,
 
 	nl = new_line_std;
 
+	if (csv_output) {
+		static int aggr_fields[] = {
+			[AGGR_GLOBAL] = 0,
+			[AGGR_THREAD] = 1,
+			[AGGR_NONE] = 1,
+			[AGGR_SOCKET] = 2,
+			[AGGR_CORE] = 2,
+		};
+
+		pm = print_metric_csv;
+		nl = new_line_csv;
+		os.nfields = 1;
+		os.nfields += aggr_fields[stat_config.aggr_mode];
+		if (counter->cgrp)
+			os.nfields++;
+		os.run = run;
+		os.ena = ena;
+	}
 	if (run == 0 || ena == 0) {
 		aggr_printout(counter, id, nr);
 
@@ -880,6 +937,8 @@ static void printout(int id, int nr, struct perf_evsel *counter, double uval,
 			fprintf(stat_config.output, "%s%s",
 				csv_sep, counter->cgrp->name);
 
+		pm(&os, NULL, NULL, "", 0);
+		print_noise(counter, noise);
 		print_running(run, ena);
 		return;
 	}
@@ -893,8 +952,7 @@ static void printout(int id, int nr, struct perf_evsel *counter, double uval,
 	out.new_line = nl;
 	out.ctx = &os;
 
-	if (!csv_output)
-		perf_stat__print_shadow_stats(counter, uval,
+	perf_stat__print_shadow_stats(counter, uval,
 				stat_config.aggr_mode == AGGR_GLOBAL ? 0 :
 				cpu_map__id_to_cpu(id),
 				&out);
-- 
2.4.3