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Message-ID: <e2c01688-d27d-51df-65eb-f7bdd26c99d0@intel.com>
Date:   Tue, 20 Dec 2022 09:35:36 +0200
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Subject: Re: [PATCH 1/3] perf tools: Set debug_peo_args and redirect_to_stderr
 to correct values in perf_quiet_option
Content-Language: en-US
To:     Yang Jihong <yangjihong1@huawei.com>, peterz@infradead.org,
        mingo@redhat.com, acme@kernel.org, mark.rutland@arm.com,
        alexander.shishkin@linux.intel.com, jolsa@kernel.org,
        namhyung@kernel.org, irogers@google.com, carsten.haitzler@arm.com,
        leo.yan@linaro.org, ravi.bangoria@amd.com, martin.lau@kernel.org,
        ak@linux.intel.com, masami.hiramatsu.pt@hitachi.com,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20221220035702.188413-1-yangjihong1@huawei.com>
 <20221220035702.188413-2-yangjihong1@huawei.com>
From:   Adrian Hunter <adrian.hunter@intel.com>
Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki,
 Business Identity Code: 0357606 - 4, Domiciled in Helsinki
In-Reply-To: <20221220035702.188413-2-yangjihong1@huawei.com>
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On 20/12/22 05:57, Yang Jihong wrote:
> When perf uses quiet mode, perf_quiet_option sets debug_peo_args to -1,
> and display_attr incorrectly determines the value of debug_peo_args.
> As a result, unexpected information is displayed.
> 
> Before:
>   # perf record --quiet -- ls > /dev/null
>   ------------------------------------------------------------
>   perf_event_attr:
>     size                             128
>     { sample_period, sample_freq }   4000
>     sample_type                      IP|TID|TIME|PERIOD
>     read_format                      ID|LOST
>     disabled                         1
>     inherit                          1
>     mmap                             1
>     comm                             1
>     freq                             1
>     enable_on_exec                   1
>     task                             1
>     precise_ip                       3
>     sample_id_all                    1
>     exclude_guest                    1
>     mmap2                            1
>     comm_exec                        1
>     ksymbol                          1
>     bpf_event                        1
>   ------------------------------------------------------------
>   ...
> 
> After:
>   # perf record --quiet -- ls > /dev/null
>   #
> 
> redirect_to_stderr is a similar problem.
> 
> Fixes: f78eaef0e049 ("perf tools: Allow to force redirect pr_debug to stderr.")
> Fixes: ccd26741f5e6 ("perf tool: Provide an option to print perf_event_open args and return value")
> Suggested-by: Adrian Hunter <adrian.hunter@intel.com>
> Signed-off-by: Yang Jihong <yangjihong1@huawei.com>

Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
>  tools/perf/util/debug.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/tools/perf/util/debug.c b/tools/perf/util/debug.c
> index 65e6c22f38e4..190e818a0717 100644
> --- a/tools/perf/util/debug.c
> +++ b/tools/perf/util/debug.c
> @@ -241,6 +241,10 @@ int perf_quiet_option(void)
>  		opt++;
>  	}
>  
> +	/* For debug variables that are used as bool types, set to 0. */
> +	redirect_to_stderr = 0;
> +	debug_peo_args = 0;
> +
>  	return 0;
>  }
>