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Subject[PATCH 1/2] perf lock contention: Fix debug stat if no contention
Date
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>
---
tools/perf/builtin-lock.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index 3c8a19ebc496..82dd2dfe5692 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");
--
2.40.0.348.gf938b09366-goog
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