perf stat: Support L2 Topdown events
The TMA method level 2 metrics is supported from the Intel Sapphire
Rapids server, which expose four L2 Topdown metrics events to user
space. There are eight L2 events in total. The other four L2 Topdown
metrics events are calculated from the corresponding L1 and the exposed
L2 events.
Now, the --topdown prints the complete top-down metrics that supported
by the CPU. For the Intel Sapphire Rapids server, there are 4 L1 events
and 8 L2 events displyed in one line.
Add a new option, --td-level, to display the top-down statistics that
equal to or lower than the input level.
The L2 event is marked only when both its L1 parent event and itself
crosse the threshold.
Here is an example:
$ perf stat --topdown --td-level=2 --no-metric-only sleep 1
Topdown accuracy may decrease when measuring long periods.
Please print the result regularly, e.g. -I1000
Performance counter stats for 'sleep 1':
16,734,390 slots
2,100,001 topdown-retiring # 12.6% retiring
2,034,376 topdown-bad-spec # 12.3% bad speculation
4,003,128 topdown-fe-bound # 24.1% frontend bound
328,125 topdown-heavy-ops # 2.0% heavy operations # 10.6% light operations
1,968,751 topdown-br-mispredict # 11.9% branch mispredict # 0.4% machine clears
2,953,127 topdown-fetch-lat # 17.8% fetch latency # 6.3% fetch bandwidth
5,906,255 topdown-mem-bound # 35.6% memory bound # 15.4% core bound
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/1612296553-21962-9-git-send-email-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 98a4dfd..08a1714 100644
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -376,7 +376,7 @@
Do not aggregate counts across all monitored CPUs.
--topdown::
-Print top down level 1 metrics if supported by the CPU. This allows to
+Print complete top-down metrics supported by the CPU. This allows to
determine bottle necks in the CPU pipeline for CPU bound workloads,
by breaking the cycles consumed down into frontend bound, backend bound,
bad speculation and retiring.
@@ -411,6 +411,18 @@
CPUs the workload runs on. If needed the CPUs can be forced using
taskset.
+--td-level::
+Print the top-down statistics that equal to or lower than the input level.
+It allows users to print the interested top-down metrics level instead of
+the complete top-down metrics.
+
+The availability of the top-down metrics level depends on the hardware. For
+example, Ice Lake only supports L1 top-down metrics. The Sapphire Rapids
+supports both L1 and L2 top-down metrics.
+
+Default: 0 means the max level that the current hardware support.
+Error out if the input is higher than the supported max level.
+
--no-merge::
Do not merge results from same PMUs.