Re: [PATCH v4 1/6] perf arm-spe: Remove unused enum value ARM_SPE_PER_CPU_MMAPS

[James Clark <james.clark@arm.com>]

On 12/04/2021 12:10, Leo Yan wrote:
> The enum value 'ARM_SPE_PER_CPU_MMAPS' is never used so remove it.

Hi Leo,

I think this causes an error when attempting to open a newly recorded file
with an old version of perf. The value ARM_SPE_AUXTRACE_PRIV_MAX is used here:

	size_t min_sz = sizeof(u64) * ARM_SPE_AUXTRACE_PRIV_MAX;
	struct perf_record_time_conv *tc = &session->time_conv;
	struct arm_spe *spe;
	int err;

	if (auxtrace_info->header.size < sizeof(struct perf_record_auxtrace_info) +
					min_sz)
		return -EINVAL;

And removing ARM_SPE_PER_CPU_MMAPS changes the value of ARM_SPE_AUXTRACE_PRIV_MAX.

At least I think that's what's causing the problem. I get this error:

	./perf report -i per-thread-spe-time.data
	0x1c0 [0x18]: failed to process type: 70 [Invalid argument]
	Error:
	failed to process sample
	# To display the perf.data header info, please use --header/--header-only options.
	#

James

> 
> Signed-off-by: Leo Yan <leo.yan@linaro.org>
> ---
>  tools/perf/util/arm-spe.h | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/tools/perf/util/arm-spe.h b/tools/perf/util/arm-spe.h
> index 98d3235781c3..105ce0ea0a01 100644
> --- a/tools/perf/util/arm-spe.h
> +++ b/tools/perf/util/arm-spe.h
> @@ -11,7 +11,6 @@
>  
>  enum {
>  	ARM_SPE_PMU_TYPE,
> -	ARM_SPE_PER_CPU_MMAPS,
>  	ARM_SPE_AUXTRACE_PRIV_MAX,
>  };
>  
>