[igt-dev] [RFC 2/3] tests/perf: new tests for parameterized OA buffer polling
Lionel Landwerlin
lionel.g.landwerlin at intel.com
Wed Dec 19 14:43:07 UTC 2018
2 new tests verifying that the OA buffer is properly checked at the
frequency specified by userspace.
Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
---
tests/perf.c | 204 +++++++++++++++++++++++++++++++++++++++++----------
1 file changed, 164 insertions(+), 40 deletions(-)
diff --git a/tests/perf.c b/tests/perf.c
index 54e7f4f4..efa9c4fd 100644
--- a/tests/perf.c
+++ b/tests/perf.c
@@ -210,6 +210,24 @@ get_oa_format(enum drm_i915_oa_format format)
return gen8_oa_formats[format];
}
+static char *
+pretty_print_oa_period(uint64_t oa_period_ns)
+{
+ static char result[100];
+ static const char *units[4] = { "ns", "us", "ms", "s" };
+ double val = oa_period_ns;
+ int iter = 0;
+
+ while (iter < (ARRAY_SIZE(units) - 1) &&
+ val >= 1000.0f) {
+ val /= 1000.0f;
+ iter++;
+ }
+
+ snprintf(result, sizeof(result), "%.3f%s", val, units[iter]);
+ return result;
+}
+
static void
__perf_close(int fd)
{
@@ -1993,15 +2011,12 @@ get_time(void)
* kernelspace.
*/
static void
-test_blocking(void)
+test_blocking(uint64_t requested_oa_period,
+ bool set_kernel_hrtimer,
+ uint64_t kernel_hrtimer,
+ bool verify_kernel_time)
{
- /* ~40 milliseconds
- *
- * Having a period somewhat > sysconf(_SC_CLK_TCK) helps to stop
- * scheduling (liable to kick in when we make blocking poll()s/reads)
- * from interfering with the test.
- */
- int oa_exponent = max_oa_exponent_for_period_lte(40000000);
+ int oa_exponent = max_oa_exponent_for_period_lte(requested_oa_period);
uint64_t oa_period = oa_exponent_to_ns(oa_exponent);
uint64_t properties[] = {
/* Include OA reports in samples */
@@ -2011,11 +2026,16 @@ test_blocking(void)
DRM_I915_PERF_PROP_OA_METRICS_SET, test_metric_set_id,
DRM_I915_PERF_PROP_OA_FORMAT, test_oa_format,
DRM_I915_PERF_PROP_OA_EXPONENT, oa_exponent,
+
+ /* Kernel configuration (optional) */
+ DRM_I915_PERF_PROP_POLL_OA_DELAY, kernel_hrtimer,
};
struct drm_i915_perf_open_param param = {
.flags = I915_PERF_FLAG_FD_CLOEXEC |
I915_PERF_FLAG_DISABLED,
- .num_properties = sizeof(properties) / 16,
+ .num_properties = (set_kernel_hrtimer ?
+ (ARRAY_SIZE(properties) / 2) :
+ ((ARRAY_SIZE(properties) / 2) - 1)),
.properties_ptr = to_user_pointer(properties),
};
uint8_t buf[1024 * 1024];
@@ -2037,7 +2057,7 @@ test_blocking(void)
* the knowledge that that the driver uses a 200Hz hrtimer (5ms period)
* to check for data and giving some time to read().
*/
- int min_iterations = (test_duration_ns / (oa_period + 6000000ull));
+ int min_iterations = (test_duration_ns / (oa_period + kernel_hrtimer + kernel_hrtimer / 5));
int64_t start, end;
int n = 0;
@@ -2047,9 +2067,10 @@ test_blocking(void)
times(&start_times);
igt_debug("tick length = %dns, test duration = %"PRIu64"ns, min iter. = %d,"
- " estimated max iter. = %d, oa_period = %"PRIu64"ns\n",
+ " estimated max iter. = %d, oa_period = %s\n",
(int)tick_ns, test_duration_ns,
- min_iterations, max_iterations, oa_period);
+ min_iterations, max_iterations,
+ pretty_print_oa_period(oa_period));
/* In the loop we perform blocking polls while the HW is sampling at
* ~25Hz, with the expectation that we spend most of our time blocked
@@ -2145,21 +2166,24 @@ test_blocking(void)
*/
igt_assert(n > (min_iterations + n_extra_iterations));
- igt_assert(kernel_ns <= (test_duration_ns / 100ull));
+ /* Only verify the amount of time spent in the kernel if
+ * requested. With the default i915/perf value, we're supposed
+ * to spend less than 1% of the time doing work, but with user
+ * specified values this is out of our hands.
+ */
+ if (verify_kernel_time)
+ igt_assert(kernel_ns <= (test_duration_ns / 100ull));
__perf_close(stream_fd);
}
static void
-test_polling(void)
+test_polling(uint64_t requested_oa_period,
+ bool set_kernel_hrtimer,
+ uint64_t kernel_hrtimer,
+ bool verify_kernel_time)
{
- /* ~40 milliseconds
- *
- * Having a period somewhat > sysconf(_SC_CLK_TCK) helps to stop
- * scheduling (liable to kick in when we make blocking poll()s/reads)
- * from interfering with the test.
- */
- int oa_exponent = max_oa_exponent_for_period_lte(40000000);
+ int oa_exponent = max_oa_exponent_for_period_lte(requested_oa_period);
uint64_t oa_period = oa_exponent_to_ns(oa_exponent);
uint64_t properties[] = {
/* Include OA reports in samples */
@@ -2169,12 +2193,17 @@ test_polling(void)
DRM_I915_PERF_PROP_OA_METRICS_SET, test_metric_set_id,
DRM_I915_PERF_PROP_OA_FORMAT, test_oa_format,
DRM_I915_PERF_PROP_OA_EXPONENT, oa_exponent,
+
+ /* Kernel configuration (optional) */
+ DRM_I915_PERF_PROP_POLL_OA_DELAY, kernel_hrtimer,
};
struct drm_i915_perf_open_param param = {
.flags = I915_PERF_FLAG_FD_CLOEXEC |
I915_PERF_FLAG_DISABLED |
I915_PERF_FLAG_FD_NONBLOCK,
- .num_properties = sizeof(properties) / 16,
+ .num_properties = (set_kernel_hrtimer ?
+ (ARRAY_SIZE(properties) / 2) :
+ ((ARRAY_SIZE(properties) / 2) - 1)),
.properties_ptr = to_user_pointer(properties),
};
uint8_t buf[1024 * 1024];
@@ -2188,24 +2217,24 @@ test_polling(void)
int n_extra_iterations = 0;
/* It's a bit tricky to put a lower limit here, but we expect a
- * relatively low latency for seeing reports, while we don't currently
- * give any control over this in the api.
+ * relatively low latency for seeing reports.
*
- * We assume a maximum latency of 6 millisecond to deliver a POLLIN and
- * read() after a new sample is written (46ms per iteration) considering
- * the knowledge that that the driver uses a 200Hz hrtimer (5ms period)
- * to check for data and giving some time to read().
+ * We assume a maximum latency of kernel_hrtimer + some margin
+ * to deliver a POLLIN and read() after a new sample is
+ * written (40ms + hrtimer + margin per iteration) considering
+ * the knowledge that that the driver uses a 200Hz hrtimer
+ * (5ms period) to check for data and giving some time to
+ * read().
*/
- int min_iterations = (test_duration_ns / (oa_period + 6000000ull));
+ int min_iterations = (test_duration_ns / (oa_period + (kernel_hrtimer + kernel_hrtimer / 5)));
int64_t start, end;
int n = 0;
stream_fd = __perf_open(drm_fd, ¶m, true /* prevent_pm */);
- times(&start_times);
-
- igt_debug("tick length = %dns, test duration = %"PRIu64"ns, min iter. = %d, max iter. = %d\n",
- (int)tick_ns, test_duration_ns,
+ igt_debug("tick length = %dns, oa period = %s, "
+ "test duration = %"PRIu64"ns, min iter. = %d, max iter. = %d\n",
+ (int)tick_ns, pretty_print_oa_period(oa_period), test_duration_ns,
min_iterations, max_iterations);
/* In the loop we perform blocking polls while the HW is sampling at
@@ -2312,8 +2341,8 @@ test_polling(void)
user_ns = (end_times.tms_utime - start_times.tms_utime) * tick_ns;
kernel_ns = (end_times.tms_stime - start_times.tms_stime) * tick_ns;
- igt_debug("%d blocking reads during test with ~25Hz OA sampling (expect no more than %d)\n",
- n, max_iterations);
+ igt_debug("%d blocking reads during test with %s OA sampling (expect no more than %d)\n",
+ n, pretty_print_oa_period(oa_period), max_iterations);
igt_debug("%d extra iterations seen, not related to periodic sampling (e.g. context switches)\n",
n_extra_iterations);
igt_debug("time in userspace = %"PRIu64"ns (+-%dns) (start utime = %d, end = %d)\n",
@@ -2333,7 +2362,13 @@ test_polling(void)
*/
igt_assert(n > (min_iterations + n_extra_iterations));
- igt_assert(kernel_ns <= (test_duration_ns / 100ull));
+ /* Only verify the amount of time spent in the kernel if
+ * requested. With the default i915/perf value, we're supposed
+ * to spend less than 1% of the time doing work, but with user
+ * specified values this is out of our hands.
+ */
+ if (verify_kernel_time)
+ igt_assert(kernel_ns <= (test_duration_ns / 100ull));
__perf_close(stream_fd);
}
@@ -4083,6 +4118,54 @@ test_sysctl_defaults(void)
igt_assert_eq(max_freq, 100000);
}
+static void
+test_invalid_poll_delay(void)
+{
+ uint64_t properties[] = {
+ /* Include OA reports in samples */
+ DRM_I915_PERF_PROP_SAMPLE_OA, true,
+
+ /* OA unit configuration */
+ DRM_I915_PERF_PROP_OA_METRICS_SET, test_metric_set_id,
+ DRM_I915_PERF_PROP_OA_FORMAT, test_oa_format,
+ DRM_I915_PERF_PROP_OA_EXPONENT, oa_exp_1_millisec,
+ DRM_I915_PERF_PROP_POLL_OA_DELAY, 10 * 1000 /* 10us */,
+ };
+ struct drm_i915_perf_open_param param = {
+ .flags = 0,
+ .num_properties = ARRAY_SIZE(properties) / 2,
+ .properties_ptr = to_user_pointer(properties),
+ };
+
+ do_ioctl_err(drm_fd, DRM_IOCTL_I915_PERF_OPEN, ¶m, EINVAL);
+}
+
+static bool
+kernel_supports_open_option(int fd, uint64_t option, uint64_t value)
+{
+ uint64_t properties[] = {
+ /* Intentionally wrong handle */
+ DRM_I915_PERF_PROP_CTX_HANDLE, UINT64_MAX,
+
+ DRM_I915_PERF_PROP_SAMPLE_OA, true,
+ DRM_I915_PERF_PROP_OA_METRICS_SET, test_metric_set_id,
+ DRM_I915_PERF_PROP_OA_FORMAT, test_oa_format,
+ DRM_I915_PERF_PROP_OA_EXPONENT, max_oa_exponent_for_period_lte(5000),
+ option, value,
+ };
+ struct drm_i915_perf_open_param param = {
+ .flags = I915_PERF_FLAG_FD_CLOEXEC,
+ .num_properties = ARRAY_SIZE(properties) / 2,
+ .properties_ptr = to_user_pointer(properties),
+ };
+ int ret;
+
+ ret = igt_ioctl(fd, DRM_IOCTL_I915_PERF_OPEN, ¶m);
+ assert(ret == -1);
+
+ return errno == ENOENT;
+}
+
igt_main
{
igt_skip_on_simulation();
@@ -4166,11 +4249,52 @@ igt_main
igt_subtest("enable-disable")
test_enable_disable();
- igt_subtest("blocking")
- test_blocking();
+ igt_subtest("blocking") {
+ test_blocking(40 * 1000 * 1000 /* 40ms oa period */,
+ false /* set_kernel_hrtimer */,
+ 5 * 1000 * 1000 /* default 5ms/200Hz hrtimer */,
+ true /* verify_kernel_time */);
+ }
+
+ igt_subtest("blocking-parameterized") {
+ igt_require(kernel_supports_open_option(drm_fd,
+ DRM_I915_PERF_PROP_POLL_OA_DELAY,
+ 40 * 1000 * 1000));
+
+ test_blocking(10 * 1000 * 1000 /* 10ms oa period */,
+ true /* set_kernel_hrtimer */,
+ 40 * 1000 * 1000 /* default 40ms hrtimer */,
+ false /* verify_kernel_time */);
+ test_blocking(500 * 1000 /* 500us oa period */,
+ true /* set_kernel_hrtimer */,
+ 1000 * 1000 /* default 1ms hrtimer */,
+ false /* verify_kernel_time */);
+ }
+
+ igt_subtest("polling") {
+ test_polling(40 * 1000 * 1000 /* 40ms oa period */,
+ false /* set_kernel_hrtimer */,
+ 5 * 1000 * 1000 /* default 5ms/200Hz hrtimer */,
+ true /* verify_kernel_time */);
+ }
+
+ igt_subtest("polling-parameterized") {
+ igt_require(kernel_supports_open_option(drm_fd,
+ DRM_I915_PERF_PROP_POLL_OA_DELAY,
+ 40 * 1000 * 1000));
+
+ test_polling(10 * 1000 * 1000 /* 10ms oa period */,
+ true /* set_kernel_hrtimer */,
+ 40 * 1000 * 1000 /* default 40ms hrtimer */,
+ false /* verify_kernel_time */);
+ test_polling(500 * 1000 /* 500us oa period */,
+ true /* set_kernel_hrtimer */,
+ 500 * 1000 /* default 500us hrtimer */,
+ false /* verify_kernel_time */);
+ }
- igt_subtest("polling")
- test_polling();
+ igt_subtest("invalid-poll-delay")
+ test_invalid_poll_delay();
igt_subtest("short-reads")
test_short_reads();
--
2.20.1
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