[PATCH] perf stat: Fix JSON output formatting in iostat_prefix()

[Suchit Karunakaran]

The iostat_prefix() function previously included a TODO noting that its output
format was incorrect in JSON mode. This patch corrects that by conditionally
formatting the prefix string based on the output mode specified in
perf_stat_config.

Signed-off-by: Suchit Karunakaran <suchitkarunakaran@xxxxxxxxx>
---
 tools/perf/arch/x86/util/iostat.c | 35 ++++++++++++++++++++-----------
 1 file changed, 23 insertions(+), 12 deletions(-)

diff --git a/tools/perf/arch/x86/util/iostat.c b/tools/perf/arch/x86/util/iostat.c
index 7442a2cd87ed..1d9c20dab5c7 100644
--- a/tools/perf/arch/x86/util/iostat.c
+++ b/tools/perf/arch/x86/util/iostat.c
@@ -403,18 +403,29 @@ void iostat_prefix(struct evlist *evlist,
 	struct iio_root_port *rp = evlist->selected->priv;
 
 	if (rp) {
-		/*
-		 * TODO: This is the incorrect format in JSON mode.
-		 *       See prepare_timestamp()
-		 */
-		if (ts)
-			sprintf(prefix, "%6lu.%09lu%s%04x:%02x%s",
-				ts->tv_sec, ts->tv_nsec,
-				config->csv_sep, rp->domain, rp->bus,
-				config->csv_sep);
-		else
-			sprintf(prefix, "%04x:%02x%s", rp->domain, rp->bus,
-				config->csv_sep);
+		if (ts) {
+			if (config->json_output)
+				sprintf(prefix,
+					"\"interval\" : %lu.%09lu, \"device\" : \"%04x:%02x\"",
+					(unsigned long)ts->tv_sec, ts->tv_nsec,
+					rp->domain, rp->bus);
+			else if (config->csv_output)
+				sprintf(prefix, "%lu.%09lu%s%04x:%02x%s",
+					(unsigned long)ts->tv_sec, ts->tv_nsec,
+					config->csv_sep,
+					rp->domain, rp->bus, config->csv_sep);
+			else
+				sprintf(prefix, "%6lu.%09lu %04x:%02x%s",
+					(unsigned long)ts->tv_sec, ts->tv_nsec,
+					rp->domain, rp->bus, config->csv_sep);
+		} else {
+			if (config->json_output)
+				sprintf(prefix, "\"device\" : \"%04x:%02x\"",
+					rp->domain, rp->bus);
+			else
+				sprintf(prefix, "%04x:%02x%s", rp->domain,
+					rp->bus, config->csv_sep);
+		}
 	}
 }
 
-- 
2.49.0