From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3F8506E235 for ; Fri, 27 Mar 2020 04:42:52 +0000 (UTC) From: Ashutosh Dixit Date: Thu, 26 Mar 2020 21:42:50 -0700 Message-Id: <20200327044250.64274-1-ashutosh.dixit@intel.com> MIME-Version: 1.0 Subject: [igt-dev] [PATCH i-g-t] tests/perf: add a test for OA data polling reads using "small" buffers List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: igt-dev-bounces@lists.freedesktop.org Sender: "igt-dev" To: igt-dev@lists.freedesktop.org List-ID: Add a test for OA data non-blocking reads using buffers smaller than the available data. This test would fail for perf revisions < 5 because poll would block even when data was available. Therefore the amount of data read was limited by the buffer size and the timer interval and it was impossible to read all available data. This issue is fixed in perf revision 5. v2: Complete rewrite, make test fail on existing kernels (Lionel) Cc: Umesh Nerlige Ramappa Reviewed-by: Ashutosh Dixit Signed-off-by: Ashutosh Dixit Signed-off-by: Lionel Landwerlin --- tests/perf.c | 69 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) diff --git a/tests/perf.c b/tests/perf.c index 724f6f809..3dc757c3b 100644 --- a/tests/perf.c +++ b/tests/perf.c @@ -2265,6 +2265,71 @@ test_polling(void) __perf_close(stream_fd); } +static void test_polling_small_buf(void) +{ + int oa_exponent = max_oa_exponent_for_period_lte(40 * 1000); /* 40us */ + 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_set->perf_oa_metrics_set, + DRM_I915_PERF_PROP_OA_FORMAT, test_set->perf_oa_format, + DRM_I915_PERF_PROP_OA_EXPONENT, oa_exponent, + }; + struct drm_i915_perf_open_param param = { + .flags = I915_PERF_FLAG_FD_CLOEXEC | + I915_PERF_FLAG_DISABLED | + I915_PERF_FLAG_FD_NONBLOCK, + .num_properties = NUM_PROPERTIES(properties), + .properties_ptr = to_user_pointer(properties), + }; + uint32_t test_duration = 80 * 1000 * 1000; + int sample_size = (sizeof(struct drm_i915_perf_record_header) + + get_oa_format(test_set->perf_oa_format).size); + int n_expected_reports = test_duration / oa_exponent_to_ns(oa_exponent); + int n_expect_read_bytes = n_expected_reports * sample_size; + uint8_t buf[1024]; + int n_bytes_read = 0; + uint32_t n_polls = 0; + struct timespec ts = {}; + + stream_fd = __perf_open(drm_fd, ¶m, true /* prevent_pm */); + do_ioctl(stream_fd, I915_PERF_IOCTL_ENABLE, 0); + + igt_nsec_elapsed(&ts); + + while (igt_nsec_elapsed(&ts) < test_duration) { + struct timespec poll_wait = { + .tv_sec = 0, + .tv_nsec = (test_duration - igt_nsec_elapsed(&ts)), + }; + struct pollfd pollfd = { .fd = stream_fd, .events = POLLIN }; + int ret; + + ret = ppoll(&pollfd, 1, &poll_wait, NULL); + + if (pollfd.revents & POLLIN) { + ret = read(stream_fd, buf, sizeof(buf)); + if (ret >= 0) + n_bytes_read += ret; + } + + n_polls++; + + igt_debug("Elapsed=%lu wait=%lu\n", igt_nsec_elapsed(&ts), poll_wait.tv_nsec); + } + + igt_info("Read %d expected %d (%.2f%% of the expected number), polls=%u\n", + n_bytes_read, n_expect_read_bytes, + n_bytes_read * 100.0f / n_expect_read_bytes, + n_polls); + + __perf_close(stream_fd); + + igt_assert(abs(n_expect_read_bytes - n_bytes_read) < (0.10 * n_expect_read_bytes)); +} + static int num_valid_reports_captured(struct drm_i915_perf_open_param *param, int64_t *duration_ns) @@ -4676,6 +4741,10 @@ igt_main igt_subtest("polling") test_polling(); + igt_describe("Test polled read with buffer size smaller than available data"); + igt_subtest("polling-small-buf") + test_polling_small_buf(); + igt_subtest("short-reads") test_short_reads(); -- 2.25.2 _______________________________________________ igt-dev mailing list igt-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/igt-dev