[Patch] perf stat: always separate stalled cycles per insn

From: Cong Wang <xiyou.wangcong@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: Cong Wang <xiyou.wangcong@gmail.com>,
	Andi Kleen <ak@linux.intel.com>, Jiri Olsa <jolsa@kernel.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>
Subject: [Patch] perf stat: always separate stalled cycles per insn
Date: Fri, 17 May 2019 15:10:39 -0700	[thread overview]
Message-ID: <20190517221039.8975-1-xiyou.wangcong@gmail.com> (raw)

The "stalled cycles per insn" is appended to "instructions" when
the CPU has this hardware counter directly. We should always make it
a separate line, which also aligns to the output when we hit the
"if (total && avg)" branch.

Before:
$ sudo perf stat --all-cpus --field-separator , --log-fd 1 -einstructions,cycles -- sleep 1
4565048704,,instructions,64114578096,100.00,1.34,insn per cycle,,
3396325133,,cycles,64146628546,100.00,,

After:
$ sudo ./tools/perf/perf stat --all-cpus --field-separator , --log-fd 1 -einstructions,cycles -- sleep 1
6721924,,instructions,24026790339,100.00,0.22,insn per cycle
,,,,,0.00,stalled cycles per insn
30939953,,cycles,24025512526,100.00,,

Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
---
 tools/perf/util/stat-shadow.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/stat-shadow.c b/tools/perf/util/stat-shadow.c
index 83d8094be4fe..5c5e012e99c4 100644
--- a/tools/perf/util/stat-shadow.c
+++ b/tools/perf/util/stat-shadow.c
@@ -800,7 +800,8 @@ void perf_stat__print_shadow_stats(struct perf_stat_config *config,
 					"stalled cycles per insn",
 					ratio);
 		} else if (have_frontend_stalled) {
-			print_metric(config, ctxp, NULL, NULL,
+			out->new_line(config, ctxp);
+			print_metric(config, ctxp, NULL, "%7.2f ",
 				     "stalled cycles per insn", 0);
 		}
 	} else if (perf_evsel__match(evsel, HARDWARE, HW_BRANCH_MISSES)) {
-- 
2.21.0

