From: Ilkka Koskinen <ilkka@os.amperecomputing.com>
To: Namhyung Kim <namhyung@kernel.org>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Ian Rogers <irogers@google.com>,
John Garry <john.g.garry@oracle.com>,
Will Deacon <will@kernel.org>,
James Clark <james.clark@linaro.org>,
Mike Leach <mike.leach@linaro.org>, Leo Yan <leo.yan@linux.dev>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Jiri Olsa <jolsa@kernel.org>,
Adrian Hunter <adrian.hunter@intel.com>,
"Liang, Kan" <kan.liang@linux.intel.com>,
Mark Rutland <mark.rutland@arm.com>
Cc: Ilkka Koskinen <ilkka@os.amperecomputing.com>,
linux-arm-kernel@lists.infradead.org,
linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/2] perf vendor events arm64 AmpereOneX: Fix frontend_bound calculation
Date: Thu, 13 Mar 2025 20:15:59 +0000 [thread overview]
Message-ID: <20250313201559.11332-3-ilkka@os.amperecomputing.com> (raw)
In-Reply-To: <20250313201559.11332-1-ilkka@os.amperecomputing.com>
frontend_bound metrics was miscalculated due to different scaling in
a couple of metrics it depends on. Change the scaling to match with
AmpereOne.
Fixes: 16438b652b46 ("perf vendor events arm64 AmpereOneX: Add core PMU events and metrics")
Signed-off-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
---
.../arch/arm64/ampere/ampereonex/metrics.json | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/tools/perf/pmu-events/arch/arm64/ampere/ampereonex/metrics.json b/tools/perf/pmu-events/arch/arm64/ampere/ampereonex/metrics.json
index c5d1d22bd034..5228f94a793f 100644
--- a/tools/perf/pmu-events/arch/arm64/ampere/ampereonex/metrics.json
+++ b/tools/perf/pmu-events/arch/arm64/ampere/ampereonex/metrics.json
@@ -229,19 +229,19 @@
},
{
"MetricName": "slots_lost_misspeculation_fraction",
- "MetricExpr": "(OP_SPEC - OP_RETIRED) / (CPU_CYCLES * #slots)",
+ "MetricExpr": "100 * (OP_SPEC - OP_RETIRED) / (CPU_CYCLES * #slots)",
"BriefDescription": "Fraction of slots lost due to misspeculation",
"DefaultMetricgroupName": "TopdownL1",
"MetricGroup": "Default;TopdownL1",
- "ScaleUnit": "100percent of slots"
+ "ScaleUnit": "1percent of slots"
},
{
"MetricName": "retired_fraction",
- "MetricExpr": "OP_RETIRED / (CPU_CYCLES * #slots)",
+ "MetricExpr": "100 * OP_RETIRED / (CPU_CYCLES * #slots)",
"BriefDescription": "Fraction of slots retiring, useful work",
"DefaultMetricgroupName": "TopdownL1",
"MetricGroup": "Default;TopdownL1",
- "ScaleUnit": "100percent of slots"
+ "ScaleUnit": "1percent of slots"
},
{
"MetricName": "backend_core",
@@ -266,7 +266,7 @@
},
{
"MetricName": "frontend_bandwidth",
- "MetricExpr": "frontend_bound - frontend_latency",
+ "MetricExpr": "frontend_bound - 100 * frontend_latency",
"BriefDescription": "Fraction of slots the CPU did not dispatch at full bandwidth - able to dispatch partial slots only (1, 2, or 3 uops)",
"MetricGroup": "TopdownL2",
"ScaleUnit": "1percent of slots"
--
2.47.0
next prev parent reply other threads:[~2025-03-13 20:12 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-13 20:15 [PATCH 0/2] perf vendor events arm64: AmpereOne/AmpereOneX: Add a new errata and fix metrics calculations Ilkka Koskinen
2025-03-13 20:15 ` [PATCH 1/2] perf vendor events arm64: AmpereOne/AmpereOneX: Mark LD_RETIRED impacted by errata Ilkka Koskinen
2025-03-18 10:48 ` James Clark
2025-03-20 20:10 ` Ilkka Koskinen
2025-03-13 20:15 ` Ilkka Koskinen [this message]
2025-03-18 10:47 ` [PATCH 2/2] perf vendor events arm64 AmpereOneX: Fix frontend_bound calculation James Clark
2025-03-21 18:30 ` [PATCH 0/2] perf vendor events arm64: AmpereOne/AmpereOneX: Add a new errata and fix metrics calculations Namhyung Kim
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