Oversaturate the virtual engines on the system and check that each
workload receives a fair share of the available GPU time.
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
---
tests/i915/gem_exec_balancer.c | 154 +++++++++++++++++++++++++++++++++
1 file changed, 154 insertions(+)
diff --git a/tests/i915/gem_exec_balancer.c b/tests/i915/gem_exec_balancer.c
index 35a032ccb..34927da54 100644
--- a/tests/i915/gem_exec_balancer.c
+++ b/tests/i915/gem_exec_balancer.c
@@ -2763,6 +2763,157 @@ static void smoketest(int i915, int timeout)
gem_close(i915, batch[0].handle);
}
+static uint32_t read_ctx_timestamp(int i915, uint32_t ctx)
+{
+ struct drm_i915_gem_relocation_entry reloc;
+ struct drm_i915_gem_exec_object2 obj = {
+ .handle = gem_create(i915, 4096),
+ .offset = 32 << 20,
+ .relocs_ptr = to_user_pointer(&reloc),
+ .relocation_count = 1,
+ };
+ struct drm_i915_gem_execbuffer2 execbuf = {
+ .buffers_ptr = to_user_pointer(&obj),
+ .buffer_count = 1,
+ .rsvd1 = ctx,
+ };
+ uint32_t *map, *cs;
+ uint32_t ts;
+
+ cs = map = gem_mmap__device_coherent(i915, obj.handle,
+ 0, 4096, PROT_WRITE);
+
+ *cs++ = 0x24 << 23 | 1 << 19 | 2; /* relative SRM */
+ *cs++ = 0x3a8; /* CTX_TIMESTAMP */
+ memset(&reloc, 0, sizeof(reloc));
+ reloc.target_handle = obj.handle;
+ reloc.presumed_offset = obj.offset;
+ reloc.offset = offset_in_page(cs);
+ reloc.delta = 4000;
+ *cs++ = obj.offset + 4000;
+ *cs++ = obj.offset >> 32;
+
+ *cs++ = MI_BATCH_BUFFER_END;
+
+ gem_execbuf(i915, &execbuf);
+ gem_sync(i915, obj.handle);
+ gem_close(i915, obj.handle);
+
+ ts = map[1000];
+ munmap(map, 4096);
+
+ return ts;
+}
+
+static int cmp_u32(const void *A, const void *B)
+{
+ const uint32_t *a = A, *b = B;
+
+ if (*a < *b)
+ return -1;
+ else if (*a > *b)
+ return 1;
+ else
+ return 0;
+}
+
+static int read_ctx_timestamp_frequency(int i915)
+{
+ int value = 12500000; /* icl!!! are you feeling alright? CTX vs CS */
+ drm_i915_getparam_t gp = {
+ .value = &value,
+ .param = I915_PARAM_CS_TIMESTAMP_FREQUENCY,
+ };
+ if (intel_gen(intel_get_drm_devid(i915)) != 11)
+ ioctl(i915, DRM_IOCTL_I915_GETPARAM, &gp);
+ return value;
+}
+
+static uint64_t div64_u64_round_up(uint64_t x, uint64_t y)
+{
+ return (x + y - 1) / y;
+}
+
+static uint64_t ticks_to_ns(int i915, uint64_t ticks)
+{
+ return div64_u64_round_up(ticks * NSEC_PER_SEC,
+ read_ctx_timestamp_frequency(i915));
+}
+
+static void __fairslice(int i915,
+ const struct i915_engine_class_instance *ci,
+ unsigned int count)
+{
+ igt_spin_t *spin = NULL;
+ uint32_t ctx[count + 1];
+ uint32_t ts[count + 1];
+
+ igt_debug("Launching %zd spinners on %s\n",
+ ARRAY_SIZE(ctx), class_to_str(ci->engine_class));
+ igt_assert(ARRAY_SIZE(ctx) >= 3);
+
+ for (int i = 0; i < ARRAY_SIZE(ctx); i++) {
+ ctx[i] = load_balancer_create(i915, ci, count);
+ if (spin == NULL) {
+ spin = __igt_spin_new(i915, .ctx = ctx[i]);
+ } else {
+ struct drm_i915_gem_execbuffer2 eb = {
+ .buffer_count = 1,
+ .buffers_ptr = to_user_pointer(&spin->obj[IGT_SPIN_BATCH]),
+ .rsvd1 = ctx[i],
+ };
+ gem_execbuf(i915, &eb);
+ }
+ }
+
+ sleep(2); /* over the course of many timeslices */
+
+ igt_assert(gem_bo_busy(i915, spin->handle));
+ igt_spin_end(spin);
+ igt_debug("Cancelled spinners\n");
+
+ for (int i = 0; i < ARRAY_SIZE(ctx); i++)
+ ts[i] = read_ctx_timestamp(i915, ctx[i]);
+
+ for (int i = 0; i < ARRAY_SIZE(ctx); i++)
+ gem_context_destroy(i915, ctx[i]);
+ igt_spin_free(i915, spin);
+
+ qsort(ts, ARRAY_SIZE(ctx), sizeof(*ts), cmp_u32);
+ igt_info("%s: [%.1f, %.1f, %.1f] ms, expect %1.fms\n",
+ class_to_str(ci->engine_class),
+ 1e-6 * ticks_to_ns(i915, ts[0]),
+ 1e-6 * ticks_to_ns(i915, ts[count / 2]),
+ 1e-6 * ticks_to_ns(i915, ts[count]),
+ 2e3 * count / ARRAY_SIZE(ctx));
+
+ igt_assert_f(ts[count], "CTX_TIMESTAMP not reported!\n");
+ igt_assert_f((ts[count] - ts[0]) * 6 < ts[count / 2],
+ "Range of timeslices greater than tolerable: %.2fms > %.2fms; unfair!\n",
+ 1e-6 * ticks_to_ns(i915, ts[count] - ts[0]),
+ 1e-6 * ticks_to_ns(i915, ts[count / 2]) / 6);
+}
+
+static void fairslice(int i915)
+{
+ /* Relative CS mmio */
+ igt_require(intel_gen(intel_get_drm_devid(i915)) >= 11);
+
+ for (int class = 0; class < 32; class++) {
+ struct i915_engine_class_instance *ci;
+ unsigned int count = 0;
+
+ ci = list_engines(i915, 1u << class, &count);
+ if (!ci || count < 2) {
+ free(ci);
+ continue;
+ }
+
+ __fairslice(i915, ci, count);
+ free(ci);
+ }
+}
+
static bool has_context_engines(int i915)
{
struct drm_i915_gem_context_param p = {
@@ -2848,6 +2999,9 @@ igt_main
full(i915, p->flags);
}
+ igt_subtest("fairslice")
+ fairslice(i915);
+
igt_subtest("nop")
nop(i915);
--
2.29.2
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