From: Namhyung Kim <namhyung@kernel.org>
Date: Mon, 27 Mar 2023 22:57:10 +0000 (-0700)
Subject: perf lock contention: Fix debug stat if no contention
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=35bf007e2ee0447166081646c0797bfa831b062f;p=linux.git
perf lock contention: Fix debug stat if no contention
It should not divide if the total number is 0. Otherwise it'd show
NaN in the bad rate output. Also add a whitespace in the "output
for debug" message.
$ sudo perf lock contention -abv true
Looking at the vmlinux_path (8 entries long)
symsrc__init: cannot get elf header.
Using /proc/kcore for kernel data
Using /proc/kallsyms for symbols
contended total wait max wait avg wait type caller
=== output for debug===
bad: 0, total: 0
bad rate: -nan % <------------------------- (here)
histogram of events caused bad sequence
acquire: 0
acquired: 0
contended: 0
release: 0
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230327225711.245738-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index 3c8a19ebc4965..82dd2dfe56921 100644
--- a/tools/perf/builtin-lock.c
+++ b/tools/perf/builtin-lock.c
@@ -1323,10 +1323,10 @@ static void print_bad_events(int bad, int total)
for (i = 0; i < BROKEN_MAX; i++)
broken += bad_hist[i];
- if (quiet || (broken == 0 && verbose <= 0))
+ if (quiet || total == 0 || (broken == 0 && verbose <= 0))
return;
- pr_info("\n=== output for debug===\n\n");
+ pr_info("\n=== output for debug ===\n\n");
pr_info("bad: %d, total: %d\n", bad, total);
pr_info("bad rate: %.2f %%\n", (double)bad / (double)total * 100);
pr_info("histogram of events caused bad sequence\n");