On 10/08/18 04:01, Chris Wilson wrote:
This exercises a special case that may be of interest, waiting for a
context that may be preempted in order to reduce the wait.
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
---
tests/gem_sync.c | 146 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 146 insertions(+)
diff --git a/tests/gem_sync.c b/tests/gem_sync.c
index 493ae61df..495ca3b53 100644
--- a/tests/gem_sync.c
+++ b/tests/gem_sync.c
@@ -409,6 +409,144 @@ store_ring(int fd, unsigned ring, int num_children, int timeout)
igt_assert_eq(intel_detect_and_clear_missed_interrupts(fd), 0);
}
+static void
+switch_ring(int fd, unsigned ring, int num_children, int timeout)
+{
+ const int gen = intel_gen(intel_get_drm_devid(fd));
+ unsigned engines[16];
+ const char *names[16];
+ int num_engines = 0;
+
+ gem_require_contexts(fd);
+
+ if (ring == ALL_ENGINES) {
+ for_each_physical_engine(fd, ring) {
+ if (!gem_can_store_dword(fd, ring))
+ continue;
+
+ names[num_engines] = e__->name;
+ engines[num_engines++] = ring;
+ if (num_engines == ARRAY_SIZE(engines))
+ break;
+ }
+
+ num_children *= num_engines;
+ } else {
+ gem_require_ring(fd, ring);
+ igt_require(gem_can_store_dword(fd, ring));
+ names[num_engines] = NULL;
+ engines[num_engines++] = ring;
+ }
+
+ intel_detect_and_clear_missed_interrupts(fd);
+ igt_fork(child, num_children) {
+ struct context {
+ struct drm_i915_gem_exec_object2 object[2];
+ struct drm_i915_gem_relocation_entry reloc[1024];
+ struct drm_i915_gem_execbuffer2 execbuf;
+ } contexts[2];
+ double start, elapsed;
+ unsigned long cycles;
+
+ for (int i = 0; i < ARRAY_SIZE(contexts); i++) {
+ const uint32_t bbe = MI_BATCH_BUFFER_END;
+ const uint32_t sz = 32 << 10;
+ struct context *c = &contexts[i];
+ uint32_t *batch, *b;
+
+ memset(&c->execbuf, 0, sizeof(c->execbuf));
+ c->execbuf.buffers_ptr = to_user_pointer(c->object);
+ c->execbuf.flags = engines[child % num_engines];
+ c->execbuf.flags |= LOCAL_I915_EXEC_NO_RELOC;
+ c->execbuf.flags |= LOCAL_I915_EXEC_HANDLE_LUT;
+ if (gen < 6)
+ c->execbuf.flags |= I915_EXEC_SECURE;
+ c->execbuf.rsvd1 = gem_context_create(fd);
+
+ memset(c->object, 0, sizeof(c->object));
+ c->object[0].handle = gem_create(fd, 4096);
+ gem_write(fd, c->object[0].handle, 0, &bbe, sizeof(bbe));
+ c->execbuf.buffer_count = 1;
+ gem_execbuf(fd, &c->execbuf);
+
+ c->object[0].flags |= EXEC_OBJECT_WRITE;
+ c->object[1].handle = gem_create(fd, sz);
+
+ c->object[1].relocs_ptr = to_user_pointer(c->reloc);
+ c->object[1].relocation_count = 1024;
+
+ batch = gem_mmap__cpu(fd, c->object[1].handle, 0, sz,
+ PROT_WRITE | PROT_READ);
+ gem_set_domain(fd, c->object[1].handle,
+ I915_GEM_DOMAIN_CPU, I915_GEM_DOMAIN_CPU);
+
+ memset(c->reloc, 0, sizeof(c->reloc));
+ b = batch;
+ for (int r = 0; r < 1024; r++) {
+ uint64_t offset;
+
+ c->reloc[r].presumed_offset = c->object[0].offset;
+ c->reloc[r].offset = (b - batch + 1) * sizeof(*batch);
+ c->reloc[r].delta = r * sizeof(uint32_t);
+ c->reloc[r].read_domains = I915_GEM_DOMAIN_INSTRUCTION;
+ c->reloc[r].write_domain = I915_GEM_DOMAIN_INSTRUCTION;
+
+ offset = c->object[0].offset + c->reloc[r].delta;
+ *b++ = MI_STORE_DWORD_IMM | (gen < 6 ? 1 << 22 : 0);
+ if (gen >= 8) {
+ *b++ = offset;
+ *b++ = offset >> 32;
+ } else if (gen >= 4) {
+ *b++ = 0;
+ *b++ = offset;
+ c->reloc[r].offset += sizeof(*batch);
+ } else {
+ b[-1] -= 1;
+ *b++ = offset;
+ }
+ *b++ = r;
+ *b++ = 0x5 << 23;
+ }
+ *b++ = MI_BATCH_BUFFER_END;
+ igt_assert((b - batch)*sizeof(uint32_t) < sz);
+ munmap(batch, sz);
+ c->execbuf.buffer_count = 2;
+ gem_execbuf(fd, &c->execbuf);
+ gem_sync(fd, c->object[1].handle);
+ }
+
+ cycles = 0;
+ elapsed = 0;
+ start = gettime();
+ do {
+ do {
+ double this;
+
+ gem_execbuf(fd, &contexts[0].execbuf);
+ gem_execbuf(fd, &contexts[1].execbuf);
I'm not sure where the preemption, mentioned in the commit message, is
coming in.
Antonio
+
+ this = gettime();
+ gem_sync(fd, contexts[1].object[1].handle);
+ elapsed += gettime() - this;
+
+ gem_sync(fd, contexts[0].object[1].handle);
+ } while (++cycles & 1023);
+ } while ((gettime() - start) < timeout);
+ igt_info("%s%sompleted %ld cycles: %.3f us\n",
+ names[child % num_engines] ?: "",
+ names[child % num_engines] ? " c" : "C",
+ cycles, elapsed*1e6/cycles);
+
+ for (int i = 0; i < ARRAY_SIZE(contexts); i++) {
+ gem_close(fd, contexts[i].object[1].handle);
+ gem_close(fd, contexts[i].object[0].handle);
+ gem_context_destroy(fd, contexts[i].execbuf.rsvd1);
+ }
+ }
+ igt_waitchildren_timeout(timeout+10, NULL);
+ igt_assert_eq(intel_detect_and_clear_missed_interrupts(fd), 0);
+}
+
static void xchg(void *array, unsigned i, unsigned j)
{
uint32_t *u32 = array;
@@ -884,6 +1022,10 @@ igt_main
wakeup_ring(fd, e->exec_id | e->flags, 150, 2);
igt_subtest_f("store-%s", e->name)
store_ring(fd, e->exec_id | e->flags, 1, 150);
+ igt_subtest_f("switch-%s", e->name)
+ switch_ring(fd, e->exec_id | e->flags, 1, 150);
+ igt_subtest_f("forked-switch-%s", e->name)
+ switch_ring(fd, e->exec_id | e->flags, ncpus, 150);
igt_subtest_f("many-%s", e->name)
store_many(fd, e->exec_id | e->flags, 150);
igt_subtest_f("forked-%s", e->name)
@@ -898,6 +1040,10 @@ igt_main
store_ring(fd, ALL_ENGINES, 1, 5);
igt_subtest("basic-many-each")
store_many(fd, ALL_ENGINES, 5);
+ igt_subtest("switch-each")
+ switch_ring(fd, ALL_ENGINES, 1, 150);
+ igt_subtest("forked-switch-each")
+ switch_ring(fd, ALL_ENGINES, ncpus, 150);
igt_subtest("forked-each")
sync_ring(fd, ALL_ENGINES, ncpus, 150);
igt_subtest("forked-store-each")
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