On 4/11/2025 12:33 AM, Riana Tauro wrote:
Hi Vinay

On 4/10/2025 7:03 AM, Vinay Belgaumkar wrote:
Add a basic test that uses PMU to read GT actual and requested
frequencies while running a workload.

v2: Rebase and comments (Riana)
v3: Address review comments (Kamil and Riana)

Cc: Lucas De Marchi <lucas.demar...@intel.com>
Cc: Rodrigo Vivi <rodrigo.v...@intel.com>
Cc: Riana Tauro <riana.ta...@intel.com>
Cc: Kamil Konieczny <kamil.koniec...@linux.intel.com>
Signed-off-by: Vinay Belgaumkar <vinay.belgaum...@intel.com>
---
  tests/intel/xe_pmu.c | 147 +++++++++++++++++++++++++++++++++++++++++++
  1 file changed, 147 insertions(+)

diff --git a/tests/intel/xe_pmu.c b/tests/intel/xe_pmu.c
index 175bbf374..589c7cbde 100644
--- a/tests/intel/xe_pmu.c
+++ b/tests/intel/xe_pmu.c
@@ -376,6 +376,94 @@ static void test_gt_c6_idle(int xe, unsigned int gt)
      close(pmu_fd);
  }
  +/**
+ * SUBTEST: gt-frequency
+ * Description: Validate we can collect accurate frequency PMU stats
+ *        while running a workload.
+ */
+static void test_gt_frequency(int fd, struct drm_xe_engine_class_instance *eci)
+{
+    struct xe_cork *cork = NULL;
+    uint64_t end[2], start[2];
+    unsigned long config_rq_freq, config_act_freq;
+    double min[2], max[2];
+    uint32_t gt = eci->gt_id;
+    uint32_t orig_min = xe_gt_get_freq(fd, eci->gt_id, "min");
+    uint32_t orig_max = xe_gt_get_freq(fd, eci->gt_id, "max");
+    uint32_t vm;
+    int pmu_fd[2];
+
+    config_rq_freq = get_event_config(gt, NULL, "gt-requested-frequency");
+    pmu_fd[0] = open_group(fd, config_rq_freq, -1);
+
+    config_act_freq = get_event_config(gt, NULL, "gt-actual-frequency");
+    pmu_fd[1] = open_group(fd, config_act_freq, pmu_fd[0]);
+
+    vm = xe_vm_create(fd, 0, 0);
+
+    cork = xe_cork_create_opts(fd, eci, vm, 1, 1);
+    xe_cork_sync_start(fd, cork);
+
+    /*
+     * Set GPU to min frequency and read PMU counters.
+     */
+    igt_assert(xe_gt_set_freq(fd, gt, "max", orig_min) > 0);
+    igt_assert(xe_gt_get_freq(fd, gt, "max") == orig_min);
+
+    pmu_read_multi(pmu_fd[0], 2, start);
+    usleep(SLEEP_DURATION * USEC_PER_SEC);
+    pmu_read_multi(pmu_fd[0], 2, end);
+
+    min[0] = (end[0] - start[0]);
+    min[1] = (end[1] - start[1]);
+
+    /*
+     * Set GPU to max frequency and read PMU counters.
+     */
+    igt_assert(xe_gt_set_freq(fd, gt, "max", orig_max) > 0);
+    igt_assert(xe_gt_get_freq(fd, gt, "max") == orig_max);
+    igt_assert(xe_gt_set_freq(fd, gt, "min", orig_max) > 0);
+    igt_assert(xe_gt_get_freq(fd, gt, "min") == orig_max);
+
+    pmu_read_multi(pmu_fd[0], 2, start);
+    usleep(SLEEP_DURATION * USEC_PER_SEC);
+    pmu_read_multi(pmu_fd[0], 2, end);
+
+    max[0] = (end[0] - start[0]);
+    max[1] = (end[1] - start[1]);
+
+    xe_cork_sync_end(fd, cork);
+
+    /*
+     * Restore min/max.
+     */
+    igt_assert(xe_gt_set_freq(fd, gt, "min", orig_min) > 0);
+    igt_assert(xe_gt_get_freq(fd, gt, "min") == orig_min);
+
+    igt_info("Minimum frequency: requested %.1f, actual %.1f\n",
+         min[0], min[1]);
+    igt_info("Maximum frequency: requested %.1f, actual %.1f\n",
+         max[0], max[1]);
+
+    close(pmu_fd[0]);
+    close(pmu_fd[1]);
+
+    if (cork)
+        xe_cork_destroy(fd, cork);
+
+    xe_vm_destroy(fd, vm);
+
+    close(pmu_fd[0]);
+    close(pmu_fd[1]);
+
+    assert_within_epsilon(min[0], orig_min, tolerance);
+    /*
+     * On thermally throttled devices we cannot be sure maximum frequency
+     * can be reached so use larger tolerance downwards.
+     */
+    assert_within_epsilon_up_down(max[0], orig_max, tolerance, 0.15f);
+}
+
  static unsigned int enable_and_provision_vfs(int fd)
  {
      unsigned int gt, num_vfs;
@@ -427,6 +515,35 @@ static void disable_vfs(int fd)
                 "Failed to restore sriov_drivers_autoprobe value\n");
  }
  +static void stash_gt_freq(int fd, uint32_t **stash_min, uint32_t **stash_max)
+{
+    int num_gts, gt;
+
+    num_gts = xe_number_gt(fd);
+
+    *stash_min = (uint32_t *) malloc(sizeof(uint32_t) * num_gts);
+    *stash_max = (uint32_t *) malloc(sizeof(uint32_t) * num_gts);
+
+    igt_skip_on(*stash_min == NULL || *stash_max == NULL);
+
+    xe_for_each_gt(fd, gt) {
+        *stash_min[gt] = xe_gt_get_freq(fd, gt, "min");
+        *stash_max[gt] = xe_gt_get_freq(fd, gt, "max");
+    }
+}
+
+static void restore_gt_freq(int fd, uint32_t *stash_min, uint32_t *stash_max)
+{
+    int gt;
+
+    xe_for_each_gt(fd, gt) {
+        xe_gt_set_freq(fd, gt, "max", stash_max[gt]);
+        xe_gt_set_freq(fd, gt, "min", stash_min[gt]);
+    }
+    free(stash_min);
+    free(stash_max);
+}
+
  igt_main
  {
      int fd, gt;
@@ -482,6 +599,36 @@ igt_main
              disable_vfs(fd);
      }
  +    igt_subtest_group {
+        bool has_freq0_node, needs_freq_restore = false;
+        uint32_t *stash_min, *stash_max;
+
+        igt_fixture {
+            has_freq0_node = xe_sysfs_gt_has_node(fd, 0, "freq0");
+        }
+
+        igt_describe("Validate PMU GT freq measured is within the tolerance");
+        igt_subtest_with_dynamic("gt-frequency") {
+            igt_skip_on(!has_freq0_node);
+            stash_gt_freq(fd, &stash_min, &stash_max);
+            needs_freq_restore = true;
+            xe_for_each_gt(fd, gt) {
Since it's one test, i thought it could be something like this, to avoid subtest group

    int orig_min = xe_gt_get_freq(fd, gt, "min");
    int orig_max = xe_gt_get_freq(fd, gt, "max");> +             igt_dynamic_f("gt%u", gt)
+                xe_for_each_engine(fd, eci) {
+                    if (gt == eci->gt_id) {
+                        test_gt_frequency(fd, eci);
+                        break;
+                    }
+                }
        xe_gt_set_freq(fd, gt, "max", orig_max);
        xe_gt_set_freq(fd, gt, "min", orig_min);

Didn't have subtest group before before, but fixture was needed to ensure freq restore happens when the test asserts due to an error. I'd like to be able to add more subtests at a later date as well, so keeping as is.

Thanks,

Vinay.


But if there are additional tests planned
Reviewed-by: Riana Tauro <riana.ta...@intel.com>>

+            }
+        }
+
+        igt_fixture {
+            if (needs_freq_restore)
+                restore_gt_freq(fd, stash_min, stash_max);
+        }
+    }
+
      igt_fixture {
          close(fd);
      }

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