linux-kernel - Re: [PATCH v1] perf test: Ignore security failures in all PMU test

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Message-ID: <ZvTojjciV9pFbGJi@google.com>
Date: Wed, 25 Sep 2024 21:52:30 -0700
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>,
	Colin Ian King <colin.i.king@...il.com>,
	Athira Jajeev <atrajeev@...ux.vnet.ibm.com>,
	linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1] perf test: Ignore security failures in all PMU test

On Wed, Sep 25, 2024 at 10:30:13AM -0700, Ian Rogers wrote:
> Refactor code to have some more error diagnosis on traps, etc. and to
> do less work on each line. Add an ignore situation for security failures.
> 
> Signed-off-by: Ian Rogers <irogers@...gle.com>
> ---
>  tools/perf/tests/shell/stat_all_pmu.sh | 52 ++++++++++++++++++++------
>  1 file changed, 40 insertions(+), 12 deletions(-)
> 
> diff --git a/tools/perf/tests/shell/stat_all_pmu.sh b/tools/perf/tests/shell/stat_all_pmu.sh
> index d2a3506e0d19..42456d89c5da 100755
> --- a/tools/perf/tests/shell/stat_all_pmu.sh
> +++ b/tools/perf/tests/shell/stat_all_pmu.sh
> @@ -1,23 +1,51 @@
> -#!/bin/sh
> +#!/bin/bash
>  # perf all PMU test
>  # SPDX-License-Identifier: GPL-2.0
>  
>  set -e
> +err=0
> +result=""
> +
> +trap_cleanup() {
> +  echo "Unexpected signal in ${FUNCNAME[1]}"
> +  echo "$result"
> +  exit 1
> +}
> +trap trap_cleanup EXIT TERM INT
>  
>  # Test all PMU events; however exclude parameterized ones (name contains '?')
> -for p in $(perf list --raw-dump pmu | sed 's/[[:graph:]]\+?[[:graph:]]\+[[:space:]]//g'); do
> +for p in $(perf list --raw-dump pmu | sed 's/[[:graph:]]\+?[[:graph:]]\+[[:space:]]//g')
> +do
>    echo "Testing $p"
>    result=$(perf stat -e "$p" true 2>&1)
> -  if ! echo "$result" | grep -q "$p" && ! echo "$result" | grep -q "<not supported>" ; then
> -    # We failed to see the event and it is supported. Possibly the workload was
> -    # too small so retry with something longer.
> -    result=$(perf stat -e "$p" perf bench internals synthesize 2>&1)
> -    if ! echo "$result" | grep -q "$p" ; then
> -      echo "Event '$p' not printed in:"
> -      echo "$result"
> -      exit 1
> -    fi
> +  if echo "$result" | grep -q "$p"
> +  then
> +    # Event seen in output.
> +    continue
> +  fi
> +  if echo "$result" | grep -q "<not supported>"
> +  then
> +    # Event not supported, so ignore.
> +    continue

I'm curious about this case.  It'll show up even if it's not supported
right?  Then the first condition would match and it doesn't reach here.

  $ perf stat -e LLC-loads true
  
   Performance counter stats for 'true':
  
     <not supported>      LLC-loads                                                             
  
         0.001213558 seconds time elapsed
  
         0.001373000 seconds user
         0.000000000 seconds sys

> +  fi
> +  if echo "$result" | grep -q "Access to performance monitoring and observability operations is limited."
> +  then
> +    # Access is limited, so ignore.
> +    continue
> +  fi
> +
> +  # We failed to see the event and it is supported. Possibly the workload was
> +  # too small so retry with something longer.

Ok, maybe we want to check "<not counted>" events specifically.

Thanks,
Namhyung


> +  result=$(perf stat -e "$p" perf bench internals synthesize 2>&1)
> +  if echo "$result" | grep -q "$p"
> +  then
> +    # Event seen in output.
> +    continue
>    fi
> +  echo "Error: event '$p' not printed in:"
> +  echo "$result"
> +  err=1
>  done
>  
> -exit 0
> +trap - EXIT TERM INT
> +exit $err
> -- 
> 2.46.0.792.g87dc391469-goog
>