2022-07-19 22:43:53

by Ian Rogers

[permalink] [raw]
Subject: [PATCH v3 3/3] perf test: Add user space counter reading tests

These tests are based on test_stat_user_read in
tools/lib/perf/tests/test-evsel.c. The tests are modified to skip if
perf_event_open fails or rdpmc isn't supported.

Signed-off-by: Ian Rogers <[email protected]>
---
tools/perf/tests/mmap-basic.c | 127 +++++++++++++++++++++++++++++++++-
1 file changed, 126 insertions(+), 1 deletion(-)

diff --git a/tools/perf/tests/mmap-basic.c b/tools/perf/tests/mmap-basic.c
index 30bbe144648a..dfb6173b2a82 100644
--- a/tools/perf/tests/mmap-basic.c
+++ b/tools/perf/tests/mmap-basic.c
@@ -170,14 +170,139 @@ static int test__basic_mmap(struct test_suite *test __maybe_unused, int subtest
return err;
}

+static int test_stat_user_read(int event)
+{
+ struct perf_counts_values counts = { .val = 0 };
+ struct perf_thread_map *threads;
+ struct perf_evsel *evsel;
+ struct perf_event_mmap_page *pc;
+ struct perf_event_attr attr = {
+ .type = PERF_TYPE_HARDWARE,
+ .config = event,
+#ifdef __aarch64__
+ .config1 = 0x2, /* Request user access */
+#endif
+ };
+ int err, i, ret = TEST_FAIL;
+ bool opened = false, mapped = false;
+
+ threads = perf_thread_map__new_dummy();
+ TEST_ASSERT_VAL("failed to create threads", threads);
+
+ perf_thread_map__set_pid(threads, 0, 0);
+
+ evsel = perf_evsel__new(&attr);
+ TEST_ASSERT_VAL("failed to create evsel", evsel);
+
+ err = perf_evsel__open(evsel, NULL, threads);
+ if (err) {
+ pr_err("failed to open evsel: %s\n", strerror(-err));
+ ret = TEST_SKIP;
+ goto out;
+ }
+ opened = true;
+
+ err = perf_evsel__mmap(evsel, 0);
+ if (err) {
+ pr_err("failed to mmap evsel: %s\n", strerror(-err));
+ goto out;
+ }
+ mapped = true;
+
+ pc = perf_evsel__mmap_base(evsel, 0, 0);
+ if (!pc) {
+ pr_err("failed to get mmapped address\n");
+ goto out;
+ }
+
+ if (!pc->cap_user_rdpmc || !pc->index) {
+ pr_err("userspace counter access not %s\n",
+ !pc->cap_user_rdpmc ? "supported" : "enabled");
+ ret = TEST_SKIP;
+ goto out;
+ }
+ if (pc->pmc_width < 32) {
+ pr_err("userspace counter width not set (%d)\n", pc->pmc_width);
+ goto out;
+ }
+
+ perf_evsel__read(evsel, 0, 0, &counts);
+ if (counts.val == 0) {
+ pr_err("failed to read value for evsel\n");
+ goto out;
+ }
+
+ for (i = 0; i < 5; i++) {
+ volatile int count = 0x10000 << i;
+ __u64 start, end, last = 0;
+
+ pr_debug("\tloop = %u, ", count);
+
+ perf_evsel__read(evsel, 0, 0, &counts);
+ start = counts.val;
+
+ while (count--) ;
+
+ perf_evsel__read(evsel, 0, 0, &counts);
+ end = counts.val;
+
+ if ((end - start) < last) {
+ pr_err("invalid counter data: end=%llu start=%llu last= %llu\n",
+ end, start, last);
+ goto out;
+ }
+ last = end - start;
+ pr_debug("count = %llu\n", end - start);
+ }
+ ret = TEST_OK;
+
+out:
+ if (mapped)
+ perf_evsel__munmap(evsel);
+ if (opened)
+ perf_evsel__close(evsel);
+ perf_evsel__delete(evsel);
+
+ perf_thread_map__put(threads);
+ return ret;
+}
+
+static int test__mmap_user_read_instr(struct test_suite *test __maybe_unused,
+ int subtest __maybe_unused)
+{
+ return test_stat_user_read(PERF_COUNT_HW_INSTRUCTIONS);
+}
+
+static int test__mmap_user_read_cycles(struct test_suite *test __maybe_unused,
+ int subtest __maybe_unused)
+{
+ return test_stat_user_read(PERF_COUNT_HW_CPU_CYCLES);
+}
+
static struct test_case tests__basic_mmap[] = {
TEST_CASE_REASON("Read samples using the mmap interface",
basic_mmap,
"permissions"),
+ TEST_CASE_REASON("User space counter reading of instructions",
+ mmap_user_read_instr,
+#if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__)
+ "permissions"
+#else
+ "unsupported"
+#endif
+ ),
+ TEST_CASE_REASON("User space counter reading of cycles",
+ mmap_user_read_cycles,
+#if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__)
+ "permissions"
+#else
+ "unsupported"
+#endif
+ ),
{ .name = NULL, }
};

struct test_suite suite__basic_mmap = {
- .desc = "Read samples using the mmap interface",
+ .desc = "mmap interface tests",
.test_cases = tests__basic_mmap,
};
--
2.37.0.170.g444d1eabd0-goog


2022-07-20 15:06:34

by Vince Weaver

[permalink] [raw]
Subject: Re: [PATCH v3 3/3] perf test: Add user space counter reading tests

On Tue, 19 Jul 2022, Ian Rogers wrote:

> These tests are based on test_stat_user_read in
> tools/lib/perf/tests/test-evsel.c. The tests are modified to skip if
> perf_event_open fails or rdpmc isn't supported.
>
> Signed-off-by: Ian Rogers <[email protected]>

> + .type = PERF_TYPE_HARDWARE,
> + .config = event,
> +#ifdef __aarch64__
> + .config1 = 0x2, /* Request user access */
> +#endif

should this value have a name rather than being a "magic constant"?

Vince

2022-07-20 15:40:02

by Ian Rogers

[permalink] [raw]
Subject: Re: [PATCH v3 3/3] perf test: Add user space counter reading tests

On Wed, Jul 20, 2022 at 7:57 AM Vince Weaver <[email protected]> wrote:
>
> On Tue, 19 Jul 2022, Ian Rogers wrote:
>
> > These tests are based on test_stat_user_read in
> > tools/lib/perf/tests/test-evsel.c. The tests are modified to skip if
> > perf_event_open fails or rdpmc isn't supported.
> >
> > Signed-off-by: Ian Rogers <[email protected]>
>
> > + .type = PERF_TYPE_HARDWARE,
> > + .config = event,
> > +#ifdef __aarch64__
> > + .config1 = 0x2, /* Request user access */
> > +#endif
>
> should this value have a name rather than being a "magic constant"?

Thanks! Firstly, this is just moving code around and so not a
regression introduced by this code:
https://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git/tree/tools/lib/perf/tests/test-evsel.c?h=perf/core#n134
I don't believe there is an existing constant for this purpose. The
kernel isn't using one either:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/kernel/perf_event.c#n309

So I agree with you and hopefully this is something ARM will clean up.

Thanks,
Ian

> Vince

2022-08-01 13:14:46

by Arnaldo Carvalho de Melo

[permalink] [raw]
Subject: Re: [PATCH v3 3/3] perf test: Add user space counter reading tests

Em Tue, Jul 19, 2022 at 03:39:46PM -0700, Ian Rogers escreveu:
> These tests are based on test_stat_user_read in
> tools/lib/perf/tests/test-evsel.c. The tests are modified to skip if
> perf_event_open fails or rdpmc isn't supported.

Thanks, tested and applied.

- Arnaldo


> Signed-off-by: Ian Rogers <[email protected]>
> ---
> tools/perf/tests/mmap-basic.c | 127 +++++++++++++++++++++++++++++++++-
> 1 file changed, 126 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/tests/mmap-basic.c b/tools/perf/tests/mmap-basic.c
> index 30bbe144648a..dfb6173b2a82 100644
> --- a/tools/perf/tests/mmap-basic.c
> +++ b/tools/perf/tests/mmap-basic.c
> @@ -170,14 +170,139 @@ static int test__basic_mmap(struct test_suite *test __maybe_unused, int subtest
> return err;
> }
>
> +static int test_stat_user_read(int event)
> +{
> + struct perf_counts_values counts = { .val = 0 };
> + struct perf_thread_map *threads;
> + struct perf_evsel *evsel;
> + struct perf_event_mmap_page *pc;
> + struct perf_event_attr attr = {
> + .type = PERF_TYPE_HARDWARE,
> + .config = event,
> +#ifdef __aarch64__
> + .config1 = 0x2, /* Request user access */
> +#endif
> + };
> + int err, i, ret = TEST_FAIL;
> + bool opened = false, mapped = false;
> +
> + threads = perf_thread_map__new_dummy();
> + TEST_ASSERT_VAL("failed to create threads", threads);
> +
> + perf_thread_map__set_pid(threads, 0, 0);
> +
> + evsel = perf_evsel__new(&attr);
> + TEST_ASSERT_VAL("failed to create evsel", evsel);
> +
> + err = perf_evsel__open(evsel, NULL, threads);
> + if (err) {
> + pr_err("failed to open evsel: %s\n", strerror(-err));
> + ret = TEST_SKIP;
> + goto out;
> + }
> + opened = true;
> +
> + err = perf_evsel__mmap(evsel, 0);
> + if (err) {
> + pr_err("failed to mmap evsel: %s\n", strerror(-err));
> + goto out;
> + }
> + mapped = true;
> +
> + pc = perf_evsel__mmap_base(evsel, 0, 0);
> + if (!pc) {
> + pr_err("failed to get mmapped address\n");
> + goto out;
> + }
> +
> + if (!pc->cap_user_rdpmc || !pc->index) {
> + pr_err("userspace counter access not %s\n",
> + !pc->cap_user_rdpmc ? "supported" : "enabled");
> + ret = TEST_SKIP;
> + goto out;
> + }
> + if (pc->pmc_width < 32) {
> + pr_err("userspace counter width not set (%d)\n", pc->pmc_width);
> + goto out;
> + }
> +
> + perf_evsel__read(evsel, 0, 0, &counts);
> + if (counts.val == 0) {
> + pr_err("failed to read value for evsel\n");
> + goto out;
> + }
> +
> + for (i = 0; i < 5; i++) {
> + volatile int count = 0x10000 << i;
> + __u64 start, end, last = 0;
> +
> + pr_debug("\tloop = %u, ", count);
> +
> + perf_evsel__read(evsel, 0, 0, &counts);
> + start = counts.val;
> +
> + while (count--) ;
> +
> + perf_evsel__read(evsel, 0, 0, &counts);
> + end = counts.val;
> +
> + if ((end - start) < last) {
> + pr_err("invalid counter data: end=%llu start=%llu last= %llu\n",
> + end, start, last);
> + goto out;
> + }
> + last = end - start;
> + pr_debug("count = %llu\n", end - start);
> + }
> + ret = TEST_OK;
> +
> +out:
> + if (mapped)
> + perf_evsel__munmap(evsel);
> + if (opened)
> + perf_evsel__close(evsel);
> + perf_evsel__delete(evsel);
> +
> + perf_thread_map__put(threads);
> + return ret;
> +}
> +
> +static int test__mmap_user_read_instr(struct test_suite *test __maybe_unused,
> + int subtest __maybe_unused)
> +{
> + return test_stat_user_read(PERF_COUNT_HW_INSTRUCTIONS);
> +}
> +
> +static int test__mmap_user_read_cycles(struct test_suite *test __maybe_unused,
> + int subtest __maybe_unused)
> +{
> + return test_stat_user_read(PERF_COUNT_HW_CPU_CYCLES);
> +}
> +
> static struct test_case tests__basic_mmap[] = {
> TEST_CASE_REASON("Read samples using the mmap interface",
> basic_mmap,
> "permissions"),
> + TEST_CASE_REASON("User space counter reading of instructions",
> + mmap_user_read_instr,
> +#if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__)
> + "permissions"
> +#else
> + "unsupported"
> +#endif
> + ),
> + TEST_CASE_REASON("User space counter reading of cycles",
> + mmap_user_read_cycles,
> +#if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__)
> + "permissions"
> +#else
> + "unsupported"
> +#endif
> + ),
> { .name = NULL, }
> };
>
> struct test_suite suite__basic_mmap = {
> - .desc = "Read samples using the mmap interface",
> + .desc = "mmap interface tests",
> .test_cases = tests__basic_mmap,
> };
> --
> 2.37.0.170.g444d1eabd0-goog

--

- Arnaldo