[igt-dev] [PATCH i-g-t v3] i915/gem_exec_balancer: Randomise bonded submission
Chris Wilson
chris at chris-wilson.co.uk
Fri May 29 15:13:46 UTC 2020
Quoting Tvrtko Ursulin (2020-05-29 16:08:25)
>
> On 29/05/2020 14:58, Chris Wilson wrote:
> > Randomly submit a paired spinner and its cancellation as a bonded
> > (submit fence) pair. Apply congestion to the engine with more bonded
> > pairs to see if the execution order fails. If we prevent a cancellation
> > from running, then the spinner will remain spinning forever.
> >
> > v2: Test both immediate submission and fenced submission
> > v3: Copy-n-paste a single context variant
> >
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> > ---
> > tests/i915/gem_exec_balancer.c | 341 +++++++++++++++++++++++++++++++++
> > 1 file changed, 341 insertions(+)
> >
> > diff --git a/tests/i915/gem_exec_balancer.c b/tests/i915/gem_exec_balancer.c
> > index 80ae82416..07fe45920 100644
> > --- a/tests/i915/gem_exec_balancer.c
> > +++ b/tests/i915/gem_exec_balancer.c
> > @@ -1154,6 +1154,342 @@ static void bonded_semaphore(int i915)
> > gem_context_destroy(i915, ctx);
> > }
> >
> > +static void __bonded_pair(int i915,
> > + const struct i915_engine_class_instance *siblings,
> > + unsigned int count,
> > + unsigned int flags,
> > + unsigned long *out)
> > +#define B_FENCE 0x1
> > +#define B_HOSTILE 0x2
> > +#define B_MANY 0x4
> > +{
> > + struct drm_i915_gem_exec_object2 batch = {};
> > + struct drm_i915_gem_execbuffer2 execbuf = {
> > + .buffers_ptr = to_user_pointer(&batch),
> > + .buffer_count = 1,
> > + };
> > + unsigned long cycles = 0;
> > + unsigned int spinner;
> > + igt_spin_t *a;
> > + int timeline;
> > + uint32_t A;
> > +
> > + srandom(getpid());
> > +
> > + spinner = IGT_SPIN_POLL_RUN;
> > + if (flags & B_HOSTILE)
> > + spinner |= IGT_SPIN_NO_PREEMPTION;
> > +
> > + A = gem_context_create(i915);
> > + set_load_balancer(i915, A, siblings, count, NULL);
> > + a = igt_spin_new(i915, A, .flags = spinner);
> > + igt_spin_end(a);
> > + gem_sync(i915, a->handle);
> > +
> > + timeline = sw_sync_timeline_create();
> > +
> > + igt_until_timeout(2) {
> > + unsigned int master;
> > + int fence;
> > +
> > + master = 1;
> > + if (flags & B_MANY)
> > + master = rand() % count + 1;
> > +
> > + fence = -1;
> > + if (flags & B_FENCE)
> > + fence = sw_sync_timeline_create_fence(timeline,
> > + cycles + 1);
> > +
> > + igt_spin_reset(a);
> > + a->execbuf.flags = master | I915_EXEC_FENCE_OUT;
> > + if (fence != -1) {
> > + a->execbuf.rsvd2 = fence;
> > + a->execbuf.flags |= I915_EXEC_FENCE_IN;
> > + }
> > + gem_execbuf_wr(i915, &a->execbuf);
> > +
> > + batch.handle = create_semaphore_to_spinner(i915, a);
> > + execbuf.rsvd1 = a->execbuf.rsvd1;
> > + execbuf.rsvd2 = a->execbuf.rsvd2 >> 32;
> > + do {
> > + execbuf.flags = rand() % count + 1;
> > + } while (execbuf.flags == master);
> > + execbuf.flags |= I915_EXEC_FENCE_SUBMIT;
> > + gem_execbuf(i915, &execbuf);
> > + gem_close(i915, batch.handle);
> > +
> > + if (fence != -1) {
> > + sw_sync_timeline_inc(timeline, 1);
> > + close(fence);
> > + }
> > + close(a->execbuf.rsvd2 >> 32);
> > +
> > + gem_sync(i915, a->handle);
> > +
> > + cycles++;
> > + }
> > +
> > + close(timeline);
> > + igt_spin_free(i915, a);
> > + gem_context_destroy(i915, A);
> > +
> > + *out = cycles;
> > +}
> > +
> > +static void bonded_pair(int i915)
> > +{
> > + static const unsigned int phases[] = {
> > + 0,
> > + B_FENCE,
> > + B_MANY,
> > + B_HOSTILE,
> > + B_HOSTILE | B_FENCE,
> > + };
> > + unsigned long *cycles;
> > +
> > + /*
> > + * The purpose of bonded submission is to execute one or more requests
> > + * concurrently. However, the very nature of that requires coordinated
> > + * submission across multiple engines.
> > + */
> > + igt_require(gem_scheduler_has_preemption(i915));
> > +
> > + cycles = mmap(0, 4096, PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
> > +
> > + for (int class = 0; class < 32; class++) {
> > + struct i915_engine_class_instance *siblings;
> > + unsigned int count;
> > +
> > + siblings = list_engines(i915, 1u << class, &count);
> > + if (count < 2)
> > + continue;
> > +
> > + igt_info("Class %u, 1 thread\n", class);
> > + for (int i = 0; i < ARRAY_SIZE(phases); i++) {
> > + cycles[0] = 0;
> > + __bonded_pair(i915,
> > + siblings, count,
> > + phases[i],
> > + &cycles[0]);
> > + gem_quiescent_gpu(i915);
> > + igt_info("%s %s %s submission, %lu cycles\n",
> > + phases[i] & B_HOSTILE ? "Non-preemptible" : "Preemptible",
> > + phases[i] & B_MANY ? "many-master" : "single-master",
> > + phases[i] & B_FENCE ? "fenced" : "immediate",
> > + cycles[0]);
> > + }
> > +
> > + igt_info("Class %u, %d threads\n", class, count + 1);
> > + for (int i = 0; i < ARRAY_SIZE(phases); i++) {
> > + memset(cycles, 0, (count + 1) * sizeof(*cycles));
> > + igt_fork(child, count + 1)
> > + __bonded_pair(i915,
> > + siblings, count,
> > + phases[i],
> > + &cycles[child]);
> > + igt_waitchildren();
> > + gem_quiescent_gpu(i915);
> > +
> > + for (int child = 1; child < count + 1; child++)
> > + cycles[0] += cycles[child];
> > +
> > + igt_info("%s %s %s submission, %lu cycles\n",
> > + phases[i] & B_HOSTILE ? "Non-preemptible" : "Preemptible",
> > + phases[i] & B_MANY ? "many-master" : "single-master",
> > + phases[i] & B_FENCE ? "fenced" : "immediate",
> > + cycles[0]);
> > + }
> > + free(siblings);
> > + }
> > +
> > + munmap(cycles, 4096);
> > +}
> > +
> > +static void __bonded_dual(int i915,
> > + const struct i915_engine_class_instance *siblings,
> > + unsigned int count,
> > + unsigned int flags,
> > + unsigned long *out)
> > +{
> > + struct drm_i915_gem_exec_object2 batch = {};
> > + struct drm_i915_gem_execbuffer2 execbuf = {
> > + .buffers_ptr = to_user_pointer(&batch),
> > + .buffer_count = 1,
> > + };
> > + unsigned long cycles = 0;
> > + unsigned int spinner;
> > + igt_spin_t *a, *b;
> > + int timeline;
> > + uint32_t A, B;
> > +
> > + srandom(getpid());
> > +
> > + spinner = IGT_SPIN_POLL_RUN;
> > + if (flags & B_HOSTILE)
> > + spinner |= IGT_SPIN_NO_PREEMPTION;
> > +
> > + A = gem_context_create(i915);
> > + set_load_balancer(i915, A, siblings, count, NULL);
> > + a = igt_spin_new(i915, A, .flags = spinner);
> > + igt_spin_end(a);
> > + gem_sync(i915, a->handle);
> > +
> > + B = gem_context_create(i915);
> > + set_load_balancer(i915, B, siblings, count, NULL);
> > + b = igt_spin_new(i915, B, .flags = spinner);
> > + igt_spin_end(b);
> > + gem_sync(i915, b->handle);
> > +
> > + timeline = sw_sync_timeline_create();
> > +
> > + igt_until_timeout(2) {
> > + unsigned int master;
> > + int fence;
> > +
> > + master = 1;
> > + if (flags & B_MANY)
> > + master = rand() % count + 1;
> > +
> > + fence = -1;
> > + if (flags & B_FENCE)
> > + fence = sw_sync_timeline_create_fence(timeline,
> > + cycles + 1);
> > +
> > + igt_spin_reset(a);
> > + a->execbuf.flags = master | I915_EXEC_FENCE_OUT;
> > + if (fence != -1) {
> > + a->execbuf.rsvd2 = fence;
> > + a->execbuf.flags |= I915_EXEC_FENCE_IN;
> > + }
> > + gem_execbuf_wr(i915, &a->execbuf);
> > +
> > + igt_spin_reset(b);
> > + b->execbuf.flags = master | I915_EXEC_FENCE_OUT;
> > + if (fence != -1) {
> > + b->execbuf.rsvd2 = fence;
> > + b->execbuf.flags |= I915_EXEC_FENCE_IN;
> > + }
> > + gem_execbuf_wr(i915, &b->execbuf);
> > +
> > + if (rand() % 1)
> > + igt_swap(a, b);
> > +
> > + batch.handle = create_semaphore_to_spinner(i915, a);
> > + execbuf.rsvd1 = a->execbuf.rsvd1;
> > + execbuf.rsvd2 = a->execbuf.rsvd2 >> 32;
> > + do {
> > + execbuf.flags = rand() % count + 1;
> > + } while (execbuf.flags == master);
> > + execbuf.flags |= I915_EXEC_FENCE_SUBMIT;
> > + gem_execbuf(i915, &execbuf);
> > + gem_close(i915, batch.handle);
> > +
> > + batch.handle = create_semaphore_to_spinner(i915, b);
> > + execbuf.rsvd1 = b->execbuf.rsvd1;
> > + execbuf.rsvd2 = b->execbuf.rsvd2 >> 32;
> > + do {
> > + execbuf.flags = rand() % count + 1;
> > + } while (execbuf.flags == master);
> > + execbuf.flags |= I915_EXEC_FENCE_SUBMIT;
> > + gem_execbuf(i915, &execbuf);
> > + gem_close(i915, batch.handle);
> > +
> > + if (fence != -1) {
> > + sw_sync_timeline_inc(timeline, 1);
> > + close(fence);
> > + }
> > + close(a->execbuf.rsvd2 >> 32);
> > + close(b->execbuf.rsvd2 >> 32);
> > +
> > + gem_sync(i915, a->handle);
> > + gem_sync(i915, b->handle);
> > +
> > + cycles++;
> > + }
> > +
> > + close(timeline);
> > +
> > + igt_spin_free(i915, a);
> > + igt_spin_free(i915, b);
> > +
> > + gem_context_destroy(i915, A);
> > + gem_context_destroy(i915, B);
> > +
> > + *out = cycles;
> > +}
> > +
> > +static void bonded_dual(int i915)
> > +{
> > + static const unsigned int phases[] = {
> > + 0,
> > + B_FENCE,
> > + B_MANY,
> > + B_HOSTILE,
> > + B_HOSTILE | B_FENCE,
> > + };
> > + unsigned long *cycles;
> > +
> > +
> > + /*
> > + * This is the same test as bonded_pair() but with the slight extra
> > + * stress of having two inflight clients and interchanging them
> > + * in a thread.
> > + */
> > + igt_require(gem_scheduler_has_preemption(i915));
> > +
> > + cycles = mmap(0, 4096, PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
> > +
> > + for (int class = 0; class < 32; class++) {
> > + struct i915_engine_class_instance *siblings;
> > + unsigned int count;
> > +
> > + siblings = list_engines(i915, 1u << class, &count);
> > + if (count < 2)
> > + continue;
> > +
> > + igt_info("Class %u, 1 thread\n", class);
> > + for (int i = 0; i < ARRAY_SIZE(phases); i++) {
> > + cycles[0] = 0;
> > + __bonded_dual(i915,
> > + siblings, count,
> > + phases[i],
> > + &cycles[0]);
> > + gem_quiescent_gpu(i915);
> > + igt_info("%s %s %s submission, %lu cycles\n",
> > + phases[i] & B_HOSTILE ? "Non-preemptible" : "Preemptible",
> > + phases[i] & B_MANY ? "many-master" : "single-master",
> > + phases[i] & B_FENCE ? "fenced" : "immediate",
> > + cycles[0]);
> > + }
> > +
> > + igt_info("Class %u, %d threads\n", class, count + 1);
> > + for (int i = 0; i < ARRAY_SIZE(phases); i++) {
> > + memset(cycles, 0, (count + 1) * sizeof(*cycles));
> > + igt_fork(child, count + 1)
> > + __bonded_dual(i915,
> > + siblings, count,
> > + phases[i],
> > + &cycles[child]);
> > + igt_waitchildren();
> > + gem_quiescent_gpu(i915);
> > +
> > + for (int child = 1; child < count + 1; child++)
> > + cycles[0] += cycles[child];
> > +
> > + igt_info("%s %s %s submission, %lu cycles\n",
> > + phases[i] & B_HOSTILE ? "Non-preemptible" : "Preemptible",
> > + phases[i] & B_MANY ? "many-master" : "single-master",
> > + phases[i] & B_FENCE ? "fenced" : "immediate",
> > + cycles[0]);
> > + }
> > +
> > + free(siblings);
> > + }
> > +
> > + munmap(cycles, 4096);
> > +}
> > +
> > static void __bonded_nohang(int i915, uint32_t ctx,
> > const struct i915_engine_class_instance *siblings,
> > unsigned int count,
> > @@ -2284,6 +2620,11 @@ igt_main
> > igt_subtest("bonded-semaphore")
> > bonded_semaphore(i915);
> >
> > + igt_subtest("bonded-pair")
> > + bonded_pair(i915);
> > + igt_subtest("bonded-dual")
> > + bonded_dual(i915);
> > +
> > igt_fixture {
> > igt_stop_hang_detector();
> > }
> >
>
>
> "Runner" (non underscore functions) could have been shared easily but okay:
Copy-n-paste, 2 keypresses. Sharing, many. I was saving Joules but not
electronvolts.
-Chris
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