[igt-dev] [PATCH i-g-t] i915/perf: Add test to query CS timestamp
Umesh Nerlige Ramappa
umesh.nerlige.ramappa at intel.com
Thu Apr 29 00:29:59 UTC 2021
Add tests to query CS timestamps for different engines.
v2:
- remove flag parameter
- assert for minimum usable values rather than maximum
v3:
- use clock id for cpu timestamps (Lionel)
- check if query is supported (Ashutosh)
- test bad queries
v4: (Chris, Tvrtko)
- cs_timestamp is a misnomer, use cs_cycles instead
- use cs cycle frequency returned in the query
- omit size parameter
v5:
- use __for_each_physical_engine (Lionel)
- check for ENODEV (Umesh)
v6: Use 2 cpu timestamps to calculate reg read time (Lionel)
v7: Refactor test code and add a spinner (Chris)
v8: Update cpu_timestamp array split into timestamp and delta
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin at intel.com>
---
include/drm-uapi/i915_drm.h | 52 ++++++++++
tests/i915/i915_query.c | 190 ++++++++++++++++++++++++++++++++++++
2 files changed, 242 insertions(+)
diff --git a/include/drm-uapi/i915_drm.h b/include/drm-uapi/i915_drm.h
index bf9ea471..1d1fe852 100644
--- a/include/drm-uapi/i915_drm.h
+++ b/include/drm-uapi/i915_drm.h
@@ -2176,6 +2176,10 @@ struct drm_i915_query_item {
#define DRM_I915_QUERY_TOPOLOGY_INFO 1
#define DRM_I915_QUERY_ENGINE_INFO 2
#define DRM_I915_QUERY_PERF_CONFIG 3
+ /**
+ * Query Command Streamer timestamp register.
+ */
+#define DRM_I915_QUERY_CS_CYCLES 4
/* Must be kept compact -- no holes and well documented */
/*
@@ -2309,6 +2313,54 @@ struct drm_i915_engine_info {
__u64 rsvd1[4];
};
+/**
+ * struct drm_i915_query_cs_cycles
+ *
+ * The query returns the command streamer cycles, the frequency that can be
+ * used to calculate the command streamer timestamp, a cpu timestamp indicating
+ * when the cs cycles was captured and a cpu_delta capturing time taken to read
+ * the cs_cycles register.
+ */
+struct drm_i915_query_cs_cycles {
+ /** Engine for which command streamer cycles is queried. */
+ struct i915_engine_class_instance engine;
+
+ /** Must be zero. */
+ __u32 flags;
+
+ /**
+ * Command streamer cycles as read from the command streamer
+ * register at 0x358 offset.
+ */
+ __u64 cs_cycles;
+
+ /** Frequency of the cs cycles in Hz. */
+ __u64 cs_frequency;
+
+ /**
+ * CPU timestamp in ns. The timestamp is captured before reading the
+ * cs_cycles register using the reference clockid set by the user.
+ */
+ __u64 cpu_timestamp;
+
+ /**
+ * Time delta in ns captured around reading the lower dword of the
+ * cs_cycles register.
+ */
+ __u64 cpu_delta;
+
+ /**
+ * Reference clock id for CPU timestamp. For definition, see
+ * clock_gettime(2) and perf_event_open(2). Supported clock ids are
+ * CLOCK_MONOTONIC, CLOCK_MONOTONIC_RAW, CLOCK_REALTIME, CLOCK_BOOTTIME,
+ * CLOCK_TAI.
+ */
+ __s32 clockid;
+
+ /** Must be zero. */
+ __u32 rsvd;
+};
+
/**
* struct drm_i915_query_engine_info
*
diff --git a/tests/i915/i915_query.c b/tests/i915/i915_query.c
index 29b938e9..3c6c5c54 100644
--- a/tests/i915/i915_query.c
+++ b/tests/i915/i915_query.c
@@ -267,6 +267,184 @@ eu_available(const struct drm_i915_query_topology_info *topo_info,
eu / 8] >> (eu % 8)) & 1;
}
+static int __query_cs_cycles(int i915, void *data)
+{
+ struct drm_i915_query_item item = {
+ .query_id = DRM_I915_QUERY_CS_CYCLES,
+ .data_ptr = to_user_pointer(data),
+ .length = data ? sizeof(struct drm_i915_query_cs_cycles) : 0,
+ };
+
+ i915_query_items(i915, &item, 1);
+
+ return item.length;
+}
+
+static bool query_cs_cycles_supported(int fd)
+{
+ return __query_cs_cycles(fd, NULL) > 0;
+}
+
+static bool engine_has_cs_cycles(int i915, uint16_t class, uint16_t instance)
+{
+ struct drm_i915_query_cs_cycles ts = {
+ .engine = { class, instance }
+ };
+
+ return __query_cs_cycles(i915, &ts) != -ENODEV;
+}
+
+static void
+__cs_cycles(int i915, struct i915_engine_class_instance *engine)
+{
+ struct drm_i915_query_cs_cycles ts1 = {};
+ struct drm_i915_query_cs_cycles ts2 = {};
+ uint64_t delta_cpu, delta_cs, delta_delta;
+ int i, usable = 0;
+ igt_spin_t *spin;
+ uint32_t ctx;
+ struct {
+ int32_t id;
+ const char *name;
+ } clock[] = {
+ { CLOCK_MONOTONIC, "CLOCK_MONOTONIC" },
+ { CLOCK_MONOTONIC_RAW, "CLOCK_MONOTONIC_RAW" },
+ { CLOCK_REALTIME, "CLOCK_REALTIME" },
+ { CLOCK_BOOTTIME, "CLOCK_BOOTTIME" },
+ { CLOCK_TAI, "CLOCK_TAI" },
+ };
+
+ igt_debug("engine[%u:%u]\n",
+ engine->engine_class,
+ engine->engine_instance);
+
+ ctx = gem_context_create_for_engine(i915,
+ engine->engine_class,
+ engine->engine_instance);
+ spin = igt_spin_new(i915, ctx);
+
+ /* Try a new clock every 10 iterations. */
+#define NUM_SNAPSHOTS 10
+ for (i = 0; i < NUM_SNAPSHOTS * ARRAY_SIZE(clock); i++) {
+ int index = i / NUM_SNAPSHOTS;
+
+ ts1.engine = *engine;
+ ts1.clockid = clock[index].id;
+
+ ts2.engine = *engine;
+ ts2.clockid = clock[index].id;
+
+ igt_assert_eq(__query_cs_cycles(i915, &ts1), sizeof(ts1));
+ igt_assert_eq(__query_cs_cycles(i915, &ts2), sizeof(ts2));
+
+ igt_debug("[1] cpu_ts before %llu, reg read time %llu\n",
+ ts1.cpu_timestamp,
+ ts1.cpu_delta);
+ igt_debug("[1] cs_ts %llu, freq %llu Hz\n",
+ ts1.cs_cycles, ts1.cs_frequency);
+
+ igt_debug("[2] cpu_ts before %llu, reg read time %llu\n",
+ ts2.cpu_timestamp,
+ ts2.cpu_delta);
+ igt_debug("[2] cs_ts %llu, freq %llu Hz\n",
+ ts2.cs_cycles, ts2.cs_frequency);
+
+ delta_cpu = ts2.cpu_timestamp - ts1.cpu_timestamp;
+ delta_cs = (ts2.cs_cycles - ts1.cs_cycles) *
+ NSEC_PER_SEC / ts1.cs_frequency;
+
+ igt_debug("delta_cpu[%lu], delta_cs[%lu]\n",
+ delta_cpu, delta_cs);
+
+ delta_delta = delta_cpu > delta_cs ?
+ delta_cpu - delta_cs :
+ delta_cs - delta_cpu;
+ igt_debug("delta_delta %lu\n", delta_delta);
+
+ if (delta_delta < 5000)
+ usable++;
+
+ /*
+ * User needs few good snapshots of the timestamps to
+ * synchronize cpu time with cs time. Check if we have enough
+ * usable values before moving to the next clockid.
+ */
+ if (!((i + 1) % NUM_SNAPSHOTS)) {
+ igt_debug("clock %s\n", clock[index].name);
+ igt_debug("usable %d\n", usable);
+ igt_assert(usable > 2);
+ usable = 0;
+ }
+ }
+
+ gem_context_destroy(i915, ctx);
+ igt_spin_free(i915, spin);
+}
+
+static void test_cs_cycles(int i915)
+{
+ const struct intel_execution_engine2 *e;
+ struct i915_engine_class_instance engine;
+
+ __for_each_physical_engine(i915, e) {
+ if (engine_has_cs_cycles(i915, e->class, e->instance)) {
+ engine.engine_class = e->class;
+ engine.engine_instance = e->instance;
+ __cs_cycles(i915, &engine);
+ }
+ }
+}
+
+static void test_cs_cycles_invalid(int i915)
+{
+ struct i915_engine_class_instance engine;
+ const struct intel_execution_engine2 *e;
+ struct drm_i915_query_cs_cycles ts = {};
+
+ /* get one engine */
+ __for_each_physical_engine(i915, e)
+ break;
+
+ /* sanity check engine selection is valid */
+ ts.engine.engine_class = e->class;
+ ts.engine.engine_instance = e->instance;
+ igt_assert_eq(__query_cs_cycles(i915, &ts), sizeof(ts));
+
+ /* bad engines */
+ ts.engine.engine_class = e->class;
+ ts.engine.engine_instance = -1;
+ igt_assert_eq(__query_cs_cycles(i915, &ts), -EINVAL);
+
+ ts.engine.engine_class = -1;
+ ts.engine.engine_instance = e->instance;
+ igt_assert_eq(__query_cs_cycles(i915, &ts), -EINVAL);
+
+ ts.engine.engine_class = -1;
+ ts.engine.engine_instance = -1;
+ igt_assert_eq(__query_cs_cycles(i915, &ts), -EINVAL);
+
+ /* non zero flags */
+ ts.flags = 1;
+ ts.engine.engine_class = e->class;
+ ts.engine.engine_instance = e->instance;
+ igt_assert_eq(__query_cs_cycles(i915, &ts), -EINVAL);
+
+ /* non zero rsvd field */
+ ts.flags = 0;
+ ts.rsvd = 1;
+ igt_assert_eq(__query_cs_cycles(i915, &ts), -EINVAL);
+
+ /* bad clockid */
+ ts.rsvd = 0;
+ ts.clockid = -1;
+ igt_assert_eq(__query_cs_cycles(i915, &ts), -EINVAL);
+
+ /* sanity check */
+ engine.engine_class = e->class;
+ engine.engine_instance = e->instance;
+ __cs_cycles(i915, &engine);
+}
+
/*
* Verify that we get coherent values between the legacy getparam slice/subslice
* masks and the new topology query.
@@ -783,6 +961,18 @@ igt_main
engines(fd);
}
+ igt_subtest_group {
+ igt_fixture {
+ igt_require(query_cs_cycles_supported(fd));
+ }
+
+ igt_subtest("cs-cycles-invalid")
+ test_cs_cycles_invalid(fd);
+
+ igt_subtest("cs-cycles")
+ test_cs_cycles(fd);
+ }
+
igt_fixture {
close(fd);
}
--
2.20.1
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