linux-kernel - Re: [PATCH v2] perf test stat: Avoid hybrid assumption when virtualized

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Z1uQWmq3KAQx1tA3@google.com>
Date: Thu, 12 Dec 2024 17:39:38 -0800
From: Namhyung Kim <namhyung@...nel.org>
To: Ian Rogers <irogers@...gle.com>
Cc: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...nel.org>,
	Mark Rutland <mark.rutland@....com>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
	Jiri Olsa <jolsa@...nel.org>,
	Adrian Hunter <adrian.hunter@...el.com>,
	Kan Liang <kan.liang@...ux.intel.com>,
	James Clark <james.clark@...aro.org>,
	linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2] perf test stat: Avoid hybrid assumption when
 virtualized

On Thu, Dec 12, 2024 at 09:33:54AM -0800, Ian Rogers wrote:
> The cycles event will fallback to task-clock in the hybrid test when
> running virtualized. Change the test to not fail for this.
> 
> Fixes: a6b8bb2addd0 ("perf test: Add a test for default perf stat command")

I cannot find this commit.

> Signed-off-by: Ian Rogers <irogers@...gle.com>

Other than that,

Acked-by: Namhyung Kim <namhyung@...nel.org>

Thanks,
Namhyung

> ---
>  tools/perf/tests/shell/stat.sh | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/tests/shell/stat.sh b/tools/perf/tests/shell/stat.sh
> index 5a2ca2bcf94d..da42427bb077 100755
> --- a/tools/perf/tests/shell/stat.sh
> +++ b/tools/perf/tests/shell/stat.sh
> @@ -163,7 +163,11 @@ test_hybrid() {
>    # Run default Perf stat
>    cycles_events=$(perf stat -- true 2>&1 | grep -E "/cycles/|  cycles  " | wc -l)
>  
> -  if [ "$pmus" -ne "$cycles_events" ]
> +  # The expectation is that default output will have a cycles events on each
> +  # hybrid PMU. In situations with no cycles PMU events, like virtualized, this
> +  # can fall back to task-clock and so the end count may be 0. Fail if neither
> +  # condition holds.
> +  if [ "$pmus" -ne "$cycles_events" ] && [ "0" -ne "$cycles_events" ]
>    then
>      echo "hybrid test [Found $pmus PMUs but $cycles_events cycles events. Failed]"
>      err=1
> -- 
> 2.47.1.613.gc27f4b7a9f-goog
>