Re: [PATCH 1/2] perf script: Fix PERF_SAMPLE_WEIGHT_STRUCT support

From: kajoljain
Date: Thu Sep 30 2021 - 06:48:30 EST




On 9/29/21 9:08 PM, kan.liang@xxxxxxxxxxxxxxx wrote:
> From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
>
> -F weight in perf script is broken.
>
> # ./perf mem record
> # ./perf script -F weight
> Samples for 'dummy:HG' event do not have WEIGHT attribute set. Cannot
> print 'weight' field.

Hi Kan,
This issue can also be reproduce in powerpc box.
Given patch fix the issue.

Reviewed-by: Kajol Jain<kjain@xxxxxxxxxxxxx>

Thanks,
Kajol Jain

>
> The sample type, PERF_SAMPLE_WEIGHT_STRUCT, is an alternative of the
> PERF_SAMPLE_WEIGHT sample type. They share the same space, weight. The
> lower 32 bits are exactly the same for both sample type. The higher 32
> bits may be different for different architecture. For a new kernel on
> x86, the PERF_SAMPLE_WEIGHT_STRUCT is used. For an old kernel or other
> ARCHs, the PERF_SAMPLE_WEIGHT is used.
>
> With -F weight, current perf script will only check the input string
> "weight" with the PERF_SAMPLE_WEIGHT sample type. Because the commit
> ea8d0ed6eae3 ("perf tools: Support PERF_SAMPLE_WEIGHT_STRUCT") didn't
> update the PERF_SAMPLE_WEIGHT_STRUCT sample type for perf script. For a
> new kernel on x86, the check fails.
>
> Use PERF_SAMPLE_WEIGHT_TYPE, which supports both sample types, to
> replace PERF_SAMPLE_WEIGHT.
>
> Reported-by: Joe Mario <jmario@xxxxxxxxxx>
> Fixes: ea8d0ed6eae3 ("perf tools: Support PERF_SAMPLE_WEIGHT_STRUCT")
> Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
> ---
> tools/perf/builtin-script.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
> index 6211d0b..9f62ac6 100644
> --- a/tools/perf/builtin-script.c
> +++ b/tools/perf/builtin-script.c
> @@ -459,7 +459,7 @@ static int evsel__check_attr(struct evsel *evsel, struct perf_session *session)
> return -EINVAL;
>
> if (PRINT_FIELD(WEIGHT) &&
> - evsel__check_stype(evsel, PERF_SAMPLE_WEIGHT, "WEIGHT", PERF_OUTPUT_WEIGHT))
> + evsel__check_stype(evsel, PERF_SAMPLE_WEIGHT_TYPE, "WEIGHT", PERF_OUTPUT_WEIGHT))
> return -EINVAL;
>
> if (PRINT_FIELD(SYM) &&
>