Re: [PATCH v1 3/7] perf cs-etm: Calculate per CPU metadata array size

Suzuki K Poulose
2021-01-11T07:30:11Z

On 1/9/21 7:44 AM, Leo Yan wrote:
> The metadata array can be extended over time and the tool, if using the
> predefined macro (like CS_ETMV4_PRIV_MAX for ETMv4) as metadata array
> size to copy data, it can cause compatible issue within different
> versions of perf tool.
>
> E.g. we recorded a data file with an old version tool, afterwards if
> use the new version perf tool to parse the file, since the metadata
> array has been extended and the macro CS_ETMV4_PRIV_MAX has been
> altered, if use it to parse the perf data with old format, this will
> lead to mismatch.
>
> To maintain backward compatibility, this patch calculates per CPU
> metadata array size on the runtime, the calculation is based on the
> info stored in the data file so that it's reliable.
>
> Signed-off-by: Leo Yan <leo.yan@linaro.org>

Looks good to me.

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