perf arm-spe: Implement find_snapshot callback
The head pointer of the AUX buffer managed by the arm_spe_pmu.c driver is not monotonically increasing, therefore the find_snapshot callback is needed in order to find the trace data within the AUX buffer and avoid wasting space in the perf.data file. The pointer is assumed to have wrapped if the buffer contains non-zero data at the end. If it has wrapped, the entire contents of the AUX buffer are stored in the perf.data file. Otherwise only the data up to the head pointer is stored. Reviewed-by:James Clark <james.clark@arm.com> Reviewed-by:
Leo Yan <leo.yan@linaro.org> Signed-off-by:
German Gomez <german.gomez@arm.com> Acked-by:
Namhyung Kim <namhyung@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: John Garry <john.garry@huawei.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Will Deacon <will@kernel.org> Cc: linux-arm-kernel@lists.infradead.org Link: https://lore.kernel.org/r/20211109163009.92072-3-german.gomez@arm.com Tested-by:
Leo Yan <leo.yan@linaro.org> Signed-off-by:
Arnaldo Carvalho de Melo <acme@redhat.com>
parent
0901b560
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