Re: [PATCH v3 3/3] perf test: Add selftest to test IBS invocation via core pmu events

[Ian Rogers]

On Tue, Apr 25, 2023 at 7:23 AM Ravi Bangoria <ravi.bangoria@xxxxxxx> wrote:
>
> IBS pmu can be invoked via fixed set of core pmu events with 'precise_ip'
> set to 1. Add a simple event open test for all these events.
>
> Without kernel fix:
>   $ sudo ./perf test -vv 76
>    76: AMD IBS via core pmu                                      :
>   --- start ---
>   test child forked, pid 6553
>   Using CPUID AuthenticAMD-25-1-1
>   type: 0x0, config: 0x0, fd: 3  -  Pass
>   type: 0x0, config: 0x1, fd: -1  -  Pass
>   type: 0x4, config: 0x76, fd: -1  -  Fail
>   type: 0x4, config: 0xc1, fd: -1  -  Fail
>   type: 0x4, config: 0x12, fd: -1  -  Pass
>   test child finished with -1
>   ---- end ----
>   AMD IBS via core pmu: FAILED!
>
> With kernel fix:
>   $ sudo ./perf test -vv 76
>    76: AMD IBS via core pmu                                      :
>   --- start ---
>   test child forked, pid 7526
>   Using CPUID AuthenticAMD-25-1-1
>   type: 0x0, config: 0x0, fd: 3  -  Pass
>   type: 0x0, config: 0x1, fd: -1  -  Pass
>   type: 0x4, config: 0x76, fd: 3  -  Pass
>   type: 0x4, config: 0xc1, fd: 3  -  Pass
>   type: 0x4, config: 0x12, fd: -1  -  Pass
>   test child finished with 0
>   ---- end ----
>   AMD IBS via core pmu: Ok
>
> Signed-off-by: Ravi Bangoria <ravi.bangoria@xxxxxxx>

Thanks Ravi, as the test is AMD specific I think it makes sense to place it in:
tools/perf/arch/x86/tests
and then to update the test list in:
tools/perf/arch/x86/tests/arch-tests.c

Thanks,
Ian

> ---
>  tools/perf/tests/Build                  |  1 +
>  tools/perf/tests/amd-ibs-via-core-pmu.c | 72 +++++++++++++++++++++++++
>  tools/perf/tests/builtin-test.c         |  1 +
>  tools/perf/tests/tests.h                |  1 +
>  4 files changed, 75 insertions(+)
>  create mode 100644 tools/perf/tests/amd-ibs-via-core-pmu.c
>
> diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build
> index fb9ac5dc4079..ff7234653503 100644
> --- a/tools/perf/tests/Build
> +++ b/tools/perf/tests/Build
> @@ -69,6 +69,7 @@ perf-y += dlfilter-test.o
>  perf-y += sigtrap.o
>  perf-y += event_groups.o
>  perf-y += symbols.o
> +perf-y += amd-ibs-via-core-pmu.o
>
>  $(OUTPUT)tests/llvm-src-base.c: tests/bpf-script-example.c tests/Build
>         $(call rule_mkdir)
> diff --git a/tools/perf/tests/amd-ibs-via-core-pmu.c b/tools/perf/tests/amd-ibs-via-core-pmu.c
> new file mode 100644
> index 000000000000..6f6eb2d84fde
> --- /dev/null
> +++ b/tools/perf/tests/amd-ibs-via-core-pmu.c
> @@ -0,0 +1,72 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include "linux/perf_event.h"
> +#include "tests.h"
> +#include "pmu.h"
> +#include "pmus.h"
> +#include "../perf-sys.h"
> +#include "debug.h"
> +
> +#define NR_SUB_TESTS 5
> +
> +static struct sub_tests {
> +       int type;
> +       unsigned long config;
> +       bool valid;
> +} sub_tests[NR_SUB_TESTS] = {
> +       { PERF_TYPE_HARDWARE, PERF_COUNT_HW_CPU_CYCLES, true },
> +       { PERF_TYPE_HARDWARE, PERF_COUNT_HW_INSTRUCTIONS, false },
> +       { PERF_TYPE_RAW, 0x076, true },
> +       { PERF_TYPE_RAW, 0x0C1, true },
> +       { PERF_TYPE_RAW, 0x012, false },
> +};
> +
> +static int event_open(int type, unsigned long config)
> +{
> +       struct perf_event_attr attr;
> +
> +       memset(&attr, 0, sizeof(struct perf_event_attr));
> +       attr.type = type;
> +       attr.size = sizeof(struct perf_event_attr);
> +       attr.config = config;
> +       attr.disabled = 1;
> +       attr.precise_ip = 1;
> +       attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_TID;
> +       attr.sample_period = 100000;
> +
> +       return sys_perf_event_open(&attr, -1, 0, -1, 0);
> +}
> +
> +static int test__amd_ibs_via_core_pmu(struct test_suite *text __maybe_unused,
> +                                     int subtest __maybe_unused)
> +{
> +       struct perf_pmu *ibs_pmu;
> +       int ret = TEST_OK;
> +       int fd, i;
> +
> +       if (list_empty(&pmus))
> +               perf_pmu__scan(NULL);
> +
> +       ibs_pmu = perf_pmu__find("ibs_op");
> +       if (!ibs_pmu)
> +               return TEST_SKIP;
> +
> +       for (i = 0; i < NR_SUB_TESTS; i++) {
> +               fd = event_open(sub_tests[i].type, sub_tests[i].config);
> +               pr_debug("type: 0x%x, config: 0x%lx, fd: %d  -  ", sub_tests[i].type,
> +                        sub_tests[i].config, fd);
> +               if ((sub_tests[i].valid && fd == -1) ||
> +                   (!sub_tests[i].valid && fd > 0)) {
> +                       pr_debug("Fail\n");
> +                       ret = TEST_FAIL;
> +               } else {
> +                       pr_debug("Pass\n");
> +               }
> +
> +               if (fd > 0)
> +                       close(fd);
> +       }
> +
> +       return ret;
> +}
> +
> +DEFINE_SUITE("AMD IBS via core pmu", amd_ibs_via_core_pmu);
> diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
> index 35cc3807cc9e..1805a4fae762 100644
> --- a/tools/perf/tests/builtin-test.c
> +++ b/tools/perf/tests/builtin-test.c
> @@ -119,6 +119,7 @@ static struct test_suite *generic_tests[] = {
>         &suite__sigtrap,
>         &suite__event_groups,
>         &suite__symbols,
> +       &suite__amd_ibs_via_core_pmu,
>         NULL,
>  };
>
> diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
> index 9a0f3904e53d..65589d40638d 100644
> --- a/tools/perf/tests/tests.h
> +++ b/tools/perf/tests/tests.h
> @@ -149,6 +149,7 @@ DECLARE_SUITE(dlfilter);
>  DECLARE_SUITE(sigtrap);
>  DECLARE_SUITE(event_groups);
>  DECLARE_SUITE(symbols);
> +DECLARE_SUITE(amd_ibs_via_core_pmu);
>
>  /*
>   * PowerPC and S390 do not support creation of instruction breakpoints using the
> --
> 2.40.0
>