linux-kernel - Re: [PATCH V2 3/5] perf tools: cs-etm: fix endless record after being terminated

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Message-ID: <20200214144308.GB30041@leoy-ThinkPad-X240s>
Date:   Fri, 14 Feb 2020 22:43:08 +0800
From:   Leo Yan <leo.yan@...aro.org>
To:     Adrian Hunter <adrian.hunter@...el.com>
Cc:     Arnaldo Carvalho de Melo <acme@...nel.org>,
        Jiri Olsa <jolsa@...hat.com>, linux-kernel@...r.kernel.org,
        Tan Xiaojun <tanxiaojun@...wei.com>,
        Wei Li <liwei391@...wei.com>
Subject: Re: [PATCH V2 3/5] perf tools: cs-etm: fix endless record after
 being terminated

On Fri, Feb 14, 2020 at 03:26:52PM +0200, Adrian Hunter wrote:
> From: Wei Li <liwei391@...wei.com>
> 
> In __cmd_record(), when receiving SIGINT(ctrl + c), a done flag will
> be set and the event list will be disabled by evlist__disable() once.
> 
> While in auxtrace_record.read_finish(), the related events will be
> enabled again, if they are continuous, the recording seems to be endless.
> 
> If the cs_etm event is disabled, we don't enable it again here.
> 
> Note: This patch is NOT tested since i don't have such a machine with
> coresight feature, but the code seems buggy same as arm-spe and intel-pt.
> 
> Signed-off-by: Wei Li <liwei391@...wei.com>
> [ahunter: removed redundant 'else' after 'return']
> Signed-off-by: Adrian Hunter <adrian.hunter@...el.com>
> Cc: stable@...r.kernel.org # 5.4+

Thanks for looping, Adrian.  Applied this patch and tested with
CoreSight on juno board, it works well:

Reviewed-and-Tested-by: Leo Yan <leo.yan@...aro.org>


> ---
>  tools/perf/arch/arm/util/cs-etm.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c
> index 2898cfdf8fe1..60141c3007a9 100644
> --- a/tools/perf/arch/arm/util/cs-etm.c
> +++ b/tools/perf/arch/arm/util/cs-etm.c
> @@ -865,9 +865,12 @@ static int cs_etm_read_finish(struct auxtrace_record *itr, int idx)
>  	struct evsel *evsel;
>  
>  	evlist__for_each_entry(ptr->evlist, evsel) {
> -		if (evsel->core.attr.type == ptr->cs_etm_pmu->type)
> +		if (evsel->core.attr.type == ptr->cs_etm_pmu->type) {
> +			if (evsel->disabled)
> +				return 0;
>  			return perf_evlist__enable_event_idx(ptr->evlist,
>  							     evsel, idx);
> +		}
>  	}
>  
>  	return -EINVAL;
> -- 
> 2.17.1
>