2024-05-07 06:51:26

by He Zhe

Subject: [PATCH] perf bench: Fix trap divide error of perf bench internals inject-build-id

perf bench internals inject-build-id suffers from the following error when
only one DSO is collected.

perf bench internals inject-build-id -v
Collected 1 DSOs
traps: internals-injec[2305] trap divide error
ip:557566ba6394 sp:7ffd4de97fe0 error:0 in perf[557566b2a000+23d000]
Build-id injection benchmark
Iteration #1
Floating point exception

This patch removes the unnecessary minus one from the divisor which also
corrects the randomization range.

Signed-off-by: He Zhe <[email protected]>
---
tools/perf/bench/inject-buildid.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/bench/inject-buildid.c b/tools/perf/bench/inject-buildid.c
index 49331743c743..a759eb2328be 100644
--- a/tools/perf/bench/inject-buildid.c
+++ b/tools/perf/bench/inject-buildid.c
@@ -362,7 +362,7 @@ static int inject_build_id(struct bench_data *data, u64 *max_rss)
return -1;

for (i = 0; i < nr_mmaps; i++) {
- int idx = rand() % (nr_dsos - 1);
+ int idx = rand() % nr_dsos;
struct bench_dso *dso = &dsos[idx];
u64 timestamp = rand() % 1000000;

--
2.25.1

2024-05-07 15:41:29

by Arnaldo Carvalho de Melo

Subject: Re: [PATCH] perf bench: Fix trap divide error of perf bench internals inject-build-id

On Tue, May 07, 2024 at 02:50:26PM +0800, He Zhe wrote:
> perf bench internals inject-build-id suffers from the following error when
> only one DSO is collected.
>
> perf bench internals inject-build-id -v
> Collected 1 DSOs
> traps: internals-injec[2305] trap divide error
> ip:557566ba6394 sp:7ffd4de97fe0 error:0 in perf[557566b2a000+23d000]
> Build-id injection benchmark
> Iteration #1
> Floating point exception
>
> This patch removes the unnecessary minus one from the divisor which also
> corrects the randomization range.

Thanks, applied to perf-tools-next, and added:

Fixes: 0bf02a0d80427f26 ("perf bench: Add build-id injection benchmark")

To make sure this ends up being picked by the stable guys and
backporters.

- Arnaldo

> Signed-off-by: He Zhe <[email protected]>
> ---
> tools/perf/bench/inject-buildid.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/perf/bench/inject-buildid.c b/tools/perf/bench/inject-buildid.c
> index 49331743c743..a759eb2328be 100644
> --- a/tools/perf/bench/inject-buildid.c
> +++ b/tools/perf/bench/inject-buildid.c
> @@ -362,7 +362,7 @@ static int inject_build_id(struct bench_data *data, u64 *max_rss)
> return -1;
>
> for (i = 0; i < nr_mmaps; i++) {
> - int idx = rand() % (nr_dsos - 1);
> + int idx = rand() % nr_dsos;
> struct bench_dso *dso = &dsos[idx];
> u64 timestamp = rand() % 1000000;
>
> --
> 2.25.1
>