diff options
| -rw-r--r-- | tests/i915/gem_exec_schedule.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/tests/i915/gem_exec_schedule.c b/tests/i915/gem_exec_schedule.c index 3df319bc..29653ae2 100644 --- a/tests/i915/gem_exec_schedule.c +++ b/tests/i915/gem_exec_schedule.c @@ -404,6 +404,68 @@ static void semaphore_userlock(int i915) igt_spin_batch_free(i915, spin); } +static void semaphore_codependency(int i915) +{ + struct { + igt_spin_t *xcs, *rcs; + } task[2]; + unsigned int engine; + int i; + + /* + * Consider two tasks, task A runs on (xcs0, rcs0) and task B + * on (xcs1, rcs0). That is they must both run a dependent + * batch on rcs0, after first running in parallel on separate + * engines. To maximise throughput, we want the shorter xcs task + * to start on rcs first. However, if we insert semaphores we may + * pick wrongly and end up running the requests in the least + * optimal order. + */ + + i = 0; + for_each_physical_engine(i915, engine) { + uint32_t ctx; + + if (engine == I915_EXEC_RENDER) + continue; + + if (!gem_can_store_dword(i915, engine)) + continue; + + ctx = gem_context_create(i915); + + task[i].xcs = + __igt_spin_batch_new(i915, + .ctx = ctx, + .engine = engine, + .flags = IGT_SPIN_POLL_RUN); + igt_spin_busywait_until_running(task[i].xcs); + + /* Common rcs tasks will be queued in FIFO */ + task[i].rcs = + __igt_spin_batch_new(i915, + .ctx = ctx, + .engine = I915_EXEC_RENDER, + .dependency = task[i].xcs->handle); + + gem_context_destroy(i915, ctx); + + if (++i == ARRAY_SIZE(task)) + break; + } + igt_require(i == ARRAY_SIZE(task)); + + /* Since task[0] was queued first, it will be first in queue for rcs */ + igt_spin_batch_end(task[1].xcs); + igt_spin_batch_end(task[1].rcs); + gem_sync(i915, task[1].rcs->handle); /* to hang if task[0] hogs rcs */ + + for (i = 0; i < ARRAY_SIZE(task); i++) { + igt_spin_batch_free(i915, task[i].xcs); + igt_spin_batch_free(i915, task[i].rcs); + } +} + static void reorder(int fd, unsigned ring, unsigned flags) #define EQUAL 1 { @@ -1393,6 +1455,8 @@ igt_main igt_subtest("semaphore-user") semaphore_userlock(fd); + igt_subtest("semaphore-codependency") + semaphore_codependency(fd); igt_subtest("smoketest-all") smoketest(fd, ALL_ENGINES, 30); |