Skip to content

Commit

Permalink
perf vendor events arm64: Update stall_slot workaround for N2 r0p3
Browse files Browse the repository at this point in the history
N2 r0p3 doesn't require the workaround [1], so gating on (#slots - 5) no
longer works because all N2s have 5 slots. Use the new expression
builtin that allows calling strcmp_cpuid_str() and comparing CPUIDs in
metric formulas.

In this case, the commented formula looks like this:

  strcmp_cpuid_str(0x410fd493)        # greater than or equal to N2 r0p3
  | strcmp_cpuid_str(0x410fd490) ^ 1  # OR NOT any version of N2

[1]: https://gitlab.arm.com/telemetry-solution/telemetry-solution/-/blob/main/data/pmu/cpu/neoverse/neoverse-n2-r0p3.json

Signed-off-by: James Clark <james.clark@arm.com>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Eduard Zingerman <eddyz87@gmail.com>
Cc: Haixin Yu <yuhaixin.yhx@linux.alibaba.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jing Zhang <renyu.zj@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nick Forrington <nick.forrington@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Sohom Datta <sohomdatta1@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230816114841.1679234-6-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
  • Loading branch information
James-A-Clark authored and acmel committed Aug 17, 2023
1 parent 9d5da30 commit d43f549
Showing 1 changed file with 4 additions and 4 deletions.
Original file line number Diff line number Diff line change
@@ -1,15 +1,15 @@
[
{
"ArchStdEvent": "FRONTEND_BOUND",
"MetricExpr": "((stall_slot_frontend) if (#slots - 5) else (stall_slot_frontend - cpu_cycles)) / (#slots * cpu_cycles)"
"MetricExpr": "((stall_slot_frontend) if (strcmp_cpuid_str(0x410fd493) | strcmp_cpuid_str(0x410fd490) ^ 1) 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))"
"MetricExpr": "(1 - op_retired / op_spec) * (1 - (stall_slot if (strcmp_cpuid_str(0x410fd493) | strcmp_cpuid_str(0x410fd490) ^ 1) 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))"
"MetricExpr": "(op_retired / op_spec) * (1 - (stall_slot if (strcmp_cpuid_str(0x410fd493) | strcmp_cpuid_str(0x410fd490) ^ 1) else (stall_slot - cpu_cycles)) / (#slots * cpu_cycles))"
},
{
"ArchStdEvent": "BACKEND_BOUND"
Expand Down Expand Up @@ -201,7 +201,7 @@
"ScaleUnit": "100%"
},
{
"MetricExpr": "OP_RETIRED / OP_SPEC * (1 - (STALL_SLOT if (#slots - 5) else (STALL_SLOT - CPU_CYCLES)) / (#slots * CPU_CYCLES))",
"MetricExpr": "OP_RETIRED / OP_SPEC * (1 - (STALL_SLOT if (strcmp_cpuid_str(0x410fd493) | strcmp_cpuid_str(0x410fd490) ^ 1) else (STALL_SLOT - CPU_CYCLES)) / (#slots * CPU_CYCLES))",
"BriefDescription": "The truly effective ratio of micro-operations executed by the CPU, which means that misprediction and stall are not included",
"MetricGroup": "PEutilization",
"MetricName": "cpu_utilization",
Expand Down

0 comments on commit d43f549

Please sign in to comment.