Re: [PATCH v2] perf/core: Skip empty AUX records with only format flags

[sashiko-bot@kernel.org]

> perf_aux_output_end() emits a PERF_RECORD_AUX when the recorded size is
> nonzero or when any flag other than PERF_AUX_FLAG_OVERWRITE is set.
> 
> PMU format flags describe how an AUX payload is encoded. TRBE driver
> sets PERF_AUX_FLAG_CORESIGHT_FORMAT_RAW for raw trace buffers, causing
> an AUX record to be emitted even when no trace data.
> 
> This is noticeable when tracing a task with strace. Ptrace stops
> repeatedly end empty AUX transactions, producing many zero-sized
> PERF_RECORD_AUX records. For example:
> 
>   perf record -e cs_etm//u -m,128M -- strace ls
> 
>   perf script -D 2>&1 |
>      awk '/PERF_RECORD_AUX offset/ {
> [ ... ]
> 
> Fixes: 547b60988e63 ("perf: aux: Add flags for the buffer format")
> Reported-by: Tamas Petz <tamas.petz@arm.com>
> Reviewed-by: James Clark <james.clark@linaro.org>
> Signed-off-by: Leo Yan <leo.yan@arm.com>

Sashiko has reviewed this patch and found no issues. It looks great!

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Sashiko AI review · https://sashiko.dev/#/patchset/20260827-perf_core_fix_zero_aux_records-v2-1-c41f2e7d056c@arm.com?part=1