This test case often fails on s390 (about 2 out of 10) because the
10% percent limit on the difference between --bpf-counters event counting
and s390 hardware counting is more than 10% in all failure cases.
Raise the limit to 20% on s390 and the test case succeeds.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: gor@linux.ibm.com
Cc: hca@linux.ibm.com
Cc: sumanthk@linux.ibm.com
Cc: svens@linux.ibm.com
Link: https://lore.kernel.org/r/20240108084009.3959211-1-tmricht@linux.ibm.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

As of now, bpf counters (bperf) don't support event groups.  But the
default perf stat includes topdown metrics if supported (on recent Intel
machines) which require groups.  That makes perf stat exiting.

  $ sudo perf stat --bpf-counter true
  bpf managed perf events do not yet support groups.

Actually the test explicitly uses cycles event only, but it missed to
pass the option when it checks the availability of the command.

Fixes: 2c0cb9f56020d2ea ("perf test: Add a shell test for 'perf stat --bpf-counters' new option")
Reviewed-by: Song Liu <song@kernel.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: bpf@vger.kernel.org
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230825164152.165610-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Running shellcheck on stat_bpf_counter.sh generates below
warning:

   In tests/shell/stat_bpf_counters.sh line 34:
   if [ "$base_cycles" == "<not" ]; then
                       ^-- SC3014 (warning): In POSIX sh, == in place of = is undefined.

   In tests/shell/stat_bpf_counters.sh line 39:
   if [ "$bpf_cycles" == "<not" ]; then
                      ^-- SC3014 (warning): In POSIX sh, == in place of = is undefined.

Fix this by using "=" instead of "==" to work for
all shells.

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Disha Goel <disgoel@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20230709182800.53002-10-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Currently the test skips with an error because == only works in bash:

  $ ./perf test 91 -v
  Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
  91: perf stat --bpf-counters test                                   :
  --- start ---
  test child forked, pid 44586
  ./tests/shell/stat_bpf_counters.sh: 26: [: -v: unexpected operator
  test child finished with -2
  ---- end ----
  perf stat --bpf-counters test: Skip

Changing == to = does the same thing, but doesn't result in an error:

  ./perf test 91 -v
  Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
  91: perf stat --bpf-counters test                                   :
  --- start ---
  test child forked, pid 45833
  Skipping: --bpf-counters not supported
    Error: unknown option `bpf-counters'
  [...]
  test child finished with -2
  ---- end ----
  perf stat --bpf-counters test: Skip

Signed-off-by: James Clark <james.clark@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org
Link: https://lore.kernel.org/r/20211028134828.65774-2-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To pick up fixes, since perf/urgent is already upstream.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

$(( .. )) is a bash feature but the test's interpreter is !/bin/sh,
switch the code to use expr.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: bpf@vger.kernel.org
Link: http://lore.kernel.org/lkml/20210617184216.2075588-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

If the test is run on a hypervisor then the cycles event may not be
counted, skip the test in this situation. Fail the test if cycles are
not counted in the subsequent bpf counter run.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: bpf@vger.kernel.org
Link: http://lore.kernel.org/lkml/20210617184216.2075588-4-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Provide additional context for when the stat bpf counters test skips.

Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: bpf@vger.kernel.org
Link: http://lore.kernel.org/lkml/20210617184216.2075588-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Add a test to compare the output of perf-stat with and without option
--bpf-counters. If the difference is more than 10%, the test is considered
as failed.

Committer testing:

  # perf test bpf-counters
  86: perf stat --bpf-counters test                                   : Ok
  # perf test -v bpf-counters
  86: perf stat --bpf-counters test                                   :
  --- start ---
  test child forked, pid 2433339
  test child finished with 0
  ---- end ----
  perf stat --bpf-counters test: Ok
  #

Signed-off-by: Song Liu <songliubraving@fb.com>
Requested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lore.kernel.org/lkml/EC00E37D-8587-4662-8E30-7AD5F874FA84@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>