[PATCH] perf test: Parse perf stat Topdown events for aarch64

[vmolnaro@redhat.com]

From: Veronika Molnarova <vmolnaro@redhat.com>

The 'perf stat' output on aarch64 machines with topdown events wasn't
counted for in the 'perf stat STD output linter' test case. Add the
topdown metric to the skip_metric list as it is done for topdown events
on other systems.

The Topdown events are also disabled on aarch64 KVM guests because the
value of caps/slots is set to 0 due to the part of the system register
being a stub. This prevents the metric for the topdown events from being
computed, leaving the 'perf stat' topdown metric without any value at
all. Add the "TopdownL1" to the skip_metric list as well to handle this
possibility.

Before aarch64:

    100: perf stat STD output linter:
    --- start ---
    test child forked, pid 403305
    Checking STD output: no args Unknown event name in TopdownL1                 #      4.3 percent of slots  slots_lost_misspeculation_fraction
    ---- end(-1) ----
    100: perf stat STD output linter                                     : FAILED!

Before aarch64 KVM:

    100: perf stat STD output linter:
    --- start ---
    test child forked, pid 404671
    Checking STD output: no args Unknown event name in TopdownL1
    ---- end(-1) ----
    100: perf stat STD output linter                                     : FAILED!

After:

    100: perf stat STD output linter:
    --- start ---
    test child forked, pid 404777
    Checking STD output: no args [Success]
    Checking STD output: system wide [Success]
    Checking STD output: interval [Success]
    Checking STD output: per thread [Success]
    Checking STD output: per node [Success]
    Checking STD output: system wide no aggregation [Success]
    Checking STD output: per core [Success]
    Checking STD output: per cache instance [Success]
    Checking STD output: per cluster [Success]
    Checking STD output: per die [Success]
    Checking STD output: per socket [Success]
    ---- end(0) ----
    100: perf stat STD output linter                                     : Ok

Signed-off-by: Veronika Molnarova <vmolnaro@redhat.com>
---
 tools/perf/tests/shell/stat+std_output.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/tests/shell/stat+std_output.sh b/tools/perf/tests/shell/stat+std_output.sh
index cbf2894b2c846a04..0f7967be60afdc7d 100755
--- a/tools/perf/tests/shell/stat+std_output.sh
+++ b/tools/perf/tests/shell/stat+std_output.sh
@@ -13,7 +13,7 @@ stat_output=$(mktemp /tmp/__perf_test.stat_output.std.XXXXX)
 
 event_name=(cpu-clock task-clock context-switches cpu-migrations page-faults stalled-cycles-frontend stalled-cycles-backend cycles instructions branches branch-misses)
 event_metric=("CPUs utilized" "CPUs utilized" "/sec" "/sec" "/sec" "frontend cycles idle" "backend cycles idle" "GHz" "insn per cycle" "/sec" "of all branches")
-skip_metric=("stalled cycles per insn" "tma_" "retiring" "frontend_bound" "bad_speculation" "backend_bound")
+skip_metric=("stalled cycles per insn" "tma_" "retiring" "frontend_bound" "bad_speculation" "backend_bound" "TopdownL1" "percent of slots")
 
 cleanup() {
   rm -f "${stat_output}"
-- 
2.43.0