Re: [PATCH 1/2] perf arm-spe: Add arm_spe_record to synthesized sample

From: German Gomez <german.gomez@arm.com>
To: Ali Saidi <alisaidi@amazon.com>,
	linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Cc: benh@kernel.crashing.org, Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@redhat.com>, Namhyung Kim <namhyung@kernel.org>,
	John Garry <john.garry@huawei.com>, Will Deacon <will@kernel.org>,
	Mathieu Poirier <mathieu.poirier@linaro.org>,
	Leo Yan <leo.yan@linaro.org>, James Clark <james.clark@arm.com>,
	Andrew Kilroy <andrew.kilroy@arm.com>
Subject: Re: [PATCH 1/2] perf arm-spe: Add arm_spe_record to synthesized sample
Date: Tue, 25 Jan 2022 20:47:39 +0000	[thread overview]
Message-ID: <5ca990a5-eedd-0edb-26d3-b5e16c36ac34@arm.com> (raw)
In-Reply-To: <20220125192016.20538-2-alisaidi@amazon.com>

Hi Ali,

On 25/01/2022 19:20, Ali Saidi wrote:
> Providing the arm_spe_record as raw data to the synthesized SPE samples
> allows perf scripts to read and separately process the data in ways
> existing perf tools don't support and mirrors functionality available
> for PEBS.
> Signed-off-by: Ali Saidi <alisaidi@amazon.com>
> ---
>  tools/perf/util/arm-spe.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c
> index d2b64e3f588b..a7499cde6fc0 100644
> --- a/tools/perf/util/arm-spe.c
> +++ b/tools/perf/util/arm-spe.c
> @@ -336,6 +336,8 @@ static int arm_spe__synth_mem_sample(struct arm_spe_queue *speq,
>  	sample.phys_addr = record->phys_addr;
>  	sample.data_src = data_src;
>  	sample.weight = record->latency;
> +	sample.raw_size = sizeof(*record);
> +	sample.raw_data = record;

Have you tried this with perf-inject? I think it would need the PERF_SAMPLE_RAW bit in the sample_type,

Although I quickly looked over the perf inject code and it looks like it's expecting some type of padding:

  // synthetic-events.c
  if (type & PERF_SAMPLE_RAW) {
    result += sizeof(u32);
    result += sample->raw_size;
  }

I'm seeing some comments in utils/event.h related to this on the intel events.

>  
>  	return arm_spe_deliver_synth_event(spe, speq, event, &sample);
>  }
> @@ -354,6 +356,8 @@ static int arm_spe__synth_branch_sample(struct arm_spe_queue *speq,
>  	sample.stream_id = spe_events_id;
>  	sample.addr = record->to_ip;
>  	sample.weight = record->latency;
> +	sample.raw_size = sizeof(*record);
> +	sample.raw_data = record;
>  
>  	return arm_spe_deliver_synth_event(spe, speq, event, &sample);
>  }
> @@ -383,6 +387,8 @@ static int arm_spe__synth_instruction_sample(struct arm_spe_queue *speq,
>  	sample.data_src = data_src;
>  	sample.period = spe->instructions_sample_period;
>  	sample.weight = record->latency;
> +	sample.raw_size = sizeof(*record);
> +	sample.raw_data = record;
>  
>  	return arm_spe_deliver_synth_event(spe, speq, event, &sample);
>  }

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