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Date:   Fri, 28 Jul 2023 11:54:11 -0300
From:   Arnaldo Carvalho de Melo <acme@kernel.org>
To:     Aditya Gupta <adityag@linux.ibm.com>
Cc:     jolsa@kernel.org, irogers@google.com, namhyung@kernel.org,
        linux-perf-users@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        maddy@linux.ibm.com, atrajeev@linux.vnet.ibm.com,
        kjain@linux.ibm.com, disgoel@linux.vnet.ibm.com,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/1] perf tests task_analyzer: Check perf build options
 for libtraceevent support
Message-ID: <ZMPWk5K63tadmDlU@kernel.org>
References: <20230725061649.34937-1-adityag@linux.ibm.com>
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Em Tue, Jul 25, 2023 at 11:46:49AM +0530, Aditya Gupta escreveu:
> Currently we depend on output of 'perf record -e "sched:sched_switch"', to
> check whether perf was built with libtraceevent support.
> 
> Instead, a more straightforward approach can be to check the build options,
> using 'perf version --build-options', to check for libtraceevent support.
> 
> When perf is compiled WITHOUT libtraceevent ('make NO_LIBTRACEEVENT=1'),
> 'perf version --build-options' outputs (output trimmed):
> 
> 	 ...
>          libtraceevent: [ OFF ]  # HAVE_LIBTRACEEVENT
> 	 ...
> 
> While, when perf is compiled WITH libtraceevent,
> 
> 'perf version --build-options' outputs:
> 
> ...
>          libtraceevent: [ on ]  # HAVE_LIBTRACEEVENT
> 	 ...
> 
> Suggested-by: Ian Rogers <irogers@google.com>
> Signed-off-by: Aditya Gupta <adityag@linux.ibm.com>
> ---
> 
>  tools/perf/tests/shell/test_task_analyzer.sh | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/tools/perf/tests/shell/test_task_analyzer.sh b/tools/perf/tests/shell/test_task_analyzer.sh
> index 0095abbe20ca..a28d784987b4 100755
> --- a/tools/perf/tests/shell/test_task_analyzer.sh
> +++ b/tools/perf/tests/shell/test_task_analyzer.sh
> @@ -52,7 +52,7 @@ find_str_or_fail() {
>  
>  # check if perf is compiled with libtraceevent support
>  skip_no_probe_record_support() {
> -	perf record -e "sched:sched_switch" -a -- sleep 1 2>&1 | grep "libtraceevent is necessary for tracepoint support" && return 2
> +	perf version --build-options | grep HAVE_LIBTRACEEVENT | grep -q OFF && return 2
>  	return 0

I'll apply this, but please consider adding a:

	perf build --has libtraceevent

subcommand to have that query made more compact and to avoid the two
extra grep.

BTW, I'll change that to:

[acme@quaco perf-tools-next]$ perf version --build-options | grep " on .* HAVE_LIBTRACEEVENT"
         libtraceevent: [ on  ]  # HAVE_LIBTRACEEVENT
[acme@quaco perf-tools-next]$

replacing "on" with OFF, so that we have just one grep.

Thanks,

- Arnaldo

>  }
>  
> -- 
> 2.41.0
> 

-- 

- Arnaldo