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perf stat: Add Topdown metrics events as default events
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The Topdown Microarchitecture Analysis (TMA) Method is a structured
analysis methodology to identify critical performance bottlenecks in
out-of-order processors. From the Ice Lake and later platforms, the
Topdown information can be retrieved from the dedicated "metrics"
register, which isn't impacted by other events. Also, the Topdown
metrics support both per thread/process and per core measuring.  Adding
Topdown metrics events as default events can enrich the default
measuring information, and would not cost any extra multiplexing.

Introduce arch_evlist__add_default_attrs() to allow architecture
specific default events. Add the Topdown metrics events in the X86
specific arch_evlist__add_default_attrs(). Other architectures can add
their own default events later separately.

With the patch:

 $ perf stat sleep 1

 Performance counter stats for 'sleep 1':

           0.82 msec task-clock:u              #    0.001 CPUs utilized
              0      context-switches:u        #    0.000 K/sec
              0      cpu-migrations:u          #    0.000 K/sec
             61      page-faults:u             #    0.074 M/sec
        319,941      cycles:u                  #    0.388 GHz
        242,802      instructions:u            #    0.76  insn per cycle
         54,380      branches:u                #   66.028 M/sec
          4,043      branch-misses:u           #    7.43% of all branches
      1,585,555      slots:u                   # 1925.189 M/sec
        238,941      topdown-retiring:u        #     15.0% retiring
        410,378      topdown-bad-spec:u        #     25.8% bad speculation
        634,222      topdown-fe-bound:u        #     39.9% frontend bound
        304,675      topdown-be-bound:u        #     19.2% backend bound

       1.001791625 seconds time elapsed

       0.000000000 seconds user
       0.001572000 seconds sys

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/20210121133752.118327-1-kan.liang@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Kan Liang authored and Arnaldo Carvalho de Melo committed Feb 3, 2021
1 parent 7efce5c commit 42641d6
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Showing 5 changed files with 26 additions and 0 deletions.
1 change: 1 addition & 0 deletions tools/perf/arch/x86/util/Build
Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@ perf-y += perf_regs.o
perf-y += topdown.o
perf-y += machine.o
perf-y += event.o
perf-y += evlist.o

perf-$(CONFIG_DWARF) += dwarf-regs.o
perf-$(CONFIG_BPF_PROLOGUE) += dwarf-regs.o
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15 changes: 15 additions & 0 deletions tools/perf/arch/x86/util/evlist.c
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@@ -0,0 +1,15 @@
// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include "util/pmu.h"
#include "util/evlist.h"
#include "util/parse-events.h"

#define TOPDOWN_L1_EVENTS "{slots,topdown-retiring,topdown-bad-spec,topdown-fe-bound,topdown-be-bound}"

int arch_evlist__add_default_attrs(struct evlist *evlist)
{
if (!pmu_have_event("cpu", "slots"))
return 0;

return parse_events(evlist, TOPDOWN_L1_EVENTS, NULL);
}
3 changes: 3 additions & 0 deletions tools/perf/builtin-stat.c
Original file line number Diff line number Diff line change
Expand Up @@ -1828,6 +1828,9 @@ static int add_default_attributes(void)
}
if (evlist__add_default_attrs(evsel_list, default_attrs1) < 0)
return -1;

if (arch_evlist__add_default_attrs(evsel_list) < 0)
return -1;
}

/* Detailed events get appended to the event list: */
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5 changes: 5 additions & 0 deletions tools/perf/util/evlist.c
Original file line number Diff line number Diff line change
Expand Up @@ -304,6 +304,11 @@ int __evlist__add_default_attrs(struct evlist *evlist, struct perf_event_attr *a
return evlist__add_attrs(evlist, attrs, nr_attrs);
}

__weak int arch_evlist__add_default_attrs(struct evlist *evlist __maybe_unused)
{
return 0;
}

struct evsel *evlist__find_tracepoint_by_id(struct evlist *evlist, int id)
{
struct evsel *evsel;
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2 changes: 2 additions & 0 deletions tools/perf/util/evlist.h
Original file line number Diff line number Diff line change
Expand Up @@ -110,6 +110,8 @@ int __evlist__add_default_attrs(struct evlist *evlist,
#define evlist__add_default_attrs(evlist, array) \
__evlist__add_default_attrs(evlist, array, ARRAY_SIZE(array))

int arch_evlist__add_default_attrs(struct evlist *evlist);

int evlist__add_dummy(struct evlist *evlist);

int evlist__add_sb_event(struct evlist *evlist, struct perf_event_attr *attr,
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