Re: [PATCH v1 5/7] perf cs-etm: Fixup PID_FMT when it is zero

Suzuki K Poulose
2021-01-11T09:48:42Z

On 1/9/21 7:44 AM, Leo Yan wrote:
> If the metadata item CS_ETM_PID_FMT/CS_ETMV4_PID_FMT is zero, this means
> the perf data file is recorded with old version tool and the tool has
> not extended to support the item.
>
> For this case, this patch fixes up PID_FMT entry to set the value as
> BIT(ETM_OPT_CTXTID), this info will be delivered to the decoder to
> extract PID from packet's field "context_id".
>
> Signed-off-by: Leo Yan <leo.yan@linaro.org>

Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>

> ---
> tools/perf/util/cs-etm.c | 19 +++++++++++++++++++
> 1 file changed, 19 insertions(+)
>
> diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c
> index 763085db29ae..8c125134a756 100644
> --- a/tools/perf/util/cs-etm.c
> +++ b/tools/perf/util/cs-etm.c
> @@ -7,6 +7,7 @@
> */
>
> #include <linux/bitops.h>
> +#include <linux/coresight-pmu.h>
> #include <linux/err.h>
> #include <linux/kernel.h>
> #include <linux/log2.h>
> @@ -2577,6 +2578,15 @@ int cs_etm__process_auxtrace_info(union perf_event *event,
> for (k = 0; k < metadata_cpu_array_size; k++)
> metadata[j][k] = ptr[i + k];
>
> + /*
> + * If the data in CS_ETM_PID_FMT is zero, means the
> + * information isn't stored in the data file, this is
> + * because the old perf tool hasn't yet supported
> + * CS_ETM_PID_FMT. Fixup the item to option "CTXTID".
> + */
> + if (!metadata[j][CS_ETM_PID_FMT])
> + metadata[j][CS_ETM_PID_FMT] = BIT(ETM_OPT_CTXTID);
> +
> /* The traceID is our handle */
> idx = metadata[j][CS_ETM_ETMTRACEIDR];
> i += metadata_cpu_array_size;
> @@ -2590,6 +2600,15 @@ int cs_etm__process_auxtrace_info(union perf_event *event,
> for (k = 0; k < metadata_cpu_array_size; k++)
> metadata[j][k] = ptr[i + k];
>
> + /*
> + * If the data in CS_ETMV4_PID_FMT is zero, means the
> + * information isn't stored in the data file, this is
> + * because the old perf tool hasn't yet supported
> + * CS_ETMV4_PID_FMT. Fixup the item to option "CTXTID".
> + */
> + if (!metadata[j][CS_ETMV4_PID_FMT])
> + metadata[j][CS_ETMV4_PID_FMT] = BIT(ETM_OPT_CTXTID);
> +
> /* The traceID is our handle */
> idx = metadata[j][CS_ETMV4_TRCTRACEIDR];
> i += metadata_cpu_array_size;
>