linux-kernel - Re: [PATCH v3 4/8] perf cs-etm: Fix bitmap for option

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Message-ID: <20210208204641.GE2077938@xps15>
Date:   Mon, 8 Feb 2021 13:46:41 -0700
From:   Mathieu Poirier <mathieu.poirier@...aro.org>
To:     Leo Yan <leo.yan@...aro.org>
Cc:     Arnaldo Carvalho de Melo <acme@...nel.org>,
        Suzuki K Poulose <suzuki.poulose@....com>,
        Mike Leach <mike.leach@...aro.org>,
        Jonathan Corbet <corbet@....net>,
        John Garry <john.garry@...wei.com>,
        Will Deacon <will@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Mark Rutland <mark.rutland@....com>,
        Jiri Olsa <jolsa@...hat.com>,
        Namhyung Kim <namhyung@...nel.org>,
        Daniel Kiss <Daniel.Kiss@....com>,
        Denis Nikitin <denik@...omium.org>,
        Al Grant <al.grant@....com>, coresight@...ts.linaro.org,
        linux-arm-kernel@...ts.infradead.org, linux-doc@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 4/8] perf cs-etm: Fix bitmap for option

On Sat, Feb 06, 2021 at 11:08:29PM +0800, Leo Yan wrote:
> From: Suzuki K Poulose <suzuki.poulose@....com>
> 
> When set option with macros ETM_OPT_CTXTID and ETM_OPT_TS, it wrongly
> takes these two values (14 and 28 prespectively) as bit masks, but
> actually both are the offset for bits.  But this doesn't lead to
> further failure due to the AND logic operation will be always true for
> ETM_OPT_CTXTID / ETM_OPT_TS.
> 
> This patch defines new independent macros (rather than using the
> "config" bits) for requesting the "contextid" and "timestamp" for
> cs_etm_set_option().
> 
> [leoy: Extract the change as a separate patch for easier review]

This should go just above your name - see below.

> Signed-off-by: Suzuki K Poulose <suzuki.poulose@....com>
> Signed-off-by: Leo Yan <leo.yan@...aro.org>
> Reviewed-by: Mike Leach <mike.leach@...aro.org>

 Signed-off-by: Suzuki K Poulose <suzuki.poulose@....com>
 [Extract the change as a separate patch for easier review]
 Signed-off-by: Leo Yan <leo.yan@...aro.org>
 Reviewed-by: Mike Leach <mike.leach@...aro.org>

> ---
>  tools/perf/arch/arm/util/cs-etm.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
> 
> diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c
> index bd446aba64f7..c25c878fd06c 100644
> --- a/tools/perf/arch/arm/util/cs-etm.c
> +++ b/tools/perf/arch/arm/util/cs-etm.c
> @@ -156,6 +156,10 @@ static int cs_etm_set_timestamp(struct auxtrace_record *itr,
>  	return err;
>  }
>  
> +#define ETM_SET_OPT_CTXTID	(1 << 0)
> +#define ETM_SET_OPT_TS		(1 << 1)
> +#define ETM_SET_OPT_MASK	(ETM_SET_OPT_CTXTID | ETM_SET_OPT_TS)
> +

I would much rather see this fixed with the BIT() macro as it is done in the
rest of this set than defining new constant.

With the above:

Reviewed-by: Mathieu Poirier <mathieu.poirier@...aro.org>

I have picked up the kernel portion of this set.  I suggest you fix the above
and send another revision to Arnaldo with my RBs.

>  static int cs_etm_set_option(struct auxtrace_record *itr,
>  			     struct evsel *evsel, u32 option)
>  {
> @@ -169,17 +173,17 @@ static int cs_etm_set_option(struct auxtrace_record *itr,
>  		    !cpu_map__has(online_cpus, i))
>  			continue;
>  
> -		if (option & ETM_OPT_CTXTID) {
> +		if (option & ETM_SET_OPT_CTXTID) {
>  			err = cs_etm_set_context_id(itr, evsel, i);
>  			if (err)
>  				goto out;
>  		}
> -		if (option & ETM_OPT_TS) {
> +		if (option & ETM_SET_OPT_TS) {
>  			err = cs_etm_set_timestamp(itr, evsel, i);
>  			if (err)
>  				goto out;
>  		}
> -		if (option & ~(ETM_OPT_CTXTID | ETM_OPT_TS))
> +		if (option & ~(ETM_SET_OPT_MASK))
>  			/* Nothing else is currently supported */
>  			goto out;
>  	}
> @@ -406,7 +410,7 @@ static int cs_etm_recording_options(struct auxtrace_record *itr,
>  		evsel__set_sample_bit(cs_etm_evsel, CPU);
>  
>  		err = cs_etm_set_option(itr, cs_etm_evsel,
> -					ETM_OPT_CTXTID | ETM_OPT_TS);
> +					ETM_SET_OPT_CTXTID | ETM_SET_OPT_TS);
>  		if (err)
>  			goto out;
>  	}
> -- 
> 2.25.1
>