[PATCH v8 4/9] perf vendor events arm64: Add topdown L1 metrics for neoverse-n2-v2

Jing Zhang
2023-01-17T07:30:29Z

Add general topdown L1 metrics for neoverse-n2-v2. Due to the wrong
count of stall_slot and stall_slot_frontend on neoverse-n2, the real
stall_slot and real stall_slot_frontend need to subtract cpu_cycles,
so overwrite the "MetricExpr" for neoverse-n2 which slots are 5.
Reference from ARM neoverse-n2 errata notice [0], D117.

Since neoverse-n2/neoverse-v2 does not yet support topdown L2, metric
groups such as Cache, TLB, Branch, InstructionsMix and PEutilization
will be added to further analysis of performance bottlenecks in the
following patches. Reference from ARM PMU guide [1][2].

[0] https://documentation-service.arm.com/static/636a66a64e6cf12278ad89cb?token=
[1] https://documentation-service.arm.com/static/628f8fa3dfaf015c2b76eae8?token=
[2] https://documentation-service.arm.com/static/62cfe21e31ea212bb6627393?token=

Signed-off-by: Jing Zhang <renyu.zj@linux.alibaba.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Acked-by: Ian Rogers <irogers@google.com>
---
.../arch/arm64/arm/neoverse-n2-v2/metrics.json | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
create mode 100644 tools/perf/pmu-events/arch/arm64/arm/neoverse-n2-v2/metrics.json

diff --git a/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2-v2/metrics.json b/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2-v2/metrics.json
new file mode 100644
index 0000000..4e7417f
--- /dev/null
+++ b/tools/perf/pmu-events/arch/arm64/arm/neoverse-n2-v2/metrics.json
@@ -0,0 +1,17 @@
+[
+ {
+ "ArchStdEvent": "FRONTEND_BOUND",
+ "MetricExpr": "((stall_slot_frontend) if (#slots - 5) else (stall_slot_frontend - cpu_cycles)) / (#slots * cpu_cycles)"
+ },
+ {
+ "ArchStdEvent": "BAD_SPECULATION",
+ "MetricExpr": "(1 - op_retired / op_spec) * (1 - (stall_slot if (#slots - 5) else (stall_slot - cpu_cycles)) / (#slots * cpu_cycles))"
+ },
+ {
+ "ArchStdEvent": "RETIRING",
+ "MetricExpr": "(op_retired / op_spec) * (1 - (stall_slot if (#slots - 5) else (stall_slot - cpu_cycles)) / (#slots * cpu_cycles))"
+ },
+ {
+ "ArchStdEvent": "BACKEND_BOUND"
+ }
+]
--
1.8.3.1