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author | Ian Rogers <irogers@google.com> | 2023-05-19 09:37:18 +0300 |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2023-06-05 21:56:14 +0300 |
commit | 6f765bbbfb3c8c5993796402a3cba311e9506eed (patch) | |
tree | 722d29bbf4ebfc6094adab39caddcf870e19056c /tools/perf/Documentation | |
parent | 269f49f9cb1e94732ec1738d0b1af4653cadd2f5 (diff) | |
download | linux-6f765bbbfb3c8c5993796402a3cba311e9506eed.tar.xz |
perf expr: Make the evaluation of & and | logical and lazy
Currently the & and | operators are only used in metric thresholds like
(from the tma_retiring metric):
tma_retiring > 0.7 | tma_heavy_operations > 0.1
Thresholds are always computed when present, but a lack of events may
mean the threshold can't be computed. This happens with the option
--metric-no-threshold for say the metric tma_retiring on Tigerlake model
CPUs.
To fully compute the threshold tma_heavy_operations is needed and it
needs the extra events of IDQ.MS_UOPS, UOPS_DECODED.DEC0,
cpu/UOPS_DECODED.DEC0,cmask=1/ and IDQ.MITE_UOPS. So
--metric-no-threshold is a useful option to reduce the number of events
needed and potentially multiplexing of events.
Rather than just fail threshold computations like this, we may know a
result from just the left or right-hand side. So, for tma_retiring if
its value is "> 0.7" we know it is over the threshold. This allows the
metric to have the threshold coloring, when possible, without all the
counters being programmed.
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Kan Liang <kan.liang@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ahmad Yasin <ahmad.yasin@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Caleb Biggers <caleb.biggers@intel.com>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Edward Baker <edward.baker@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Perry Taylor <perry.taylor@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Samantha Alt <samantha.alt@intel.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Weilin Wang <weilin.wang@intel.com>
Link: https://lore.kernel.org/r/20230519063719.1029596-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/Documentation')
0 files changed, 0 insertions, 0 deletions