From dee4a0f8e70db36105e43dba5652737df5812190 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Tue, 25 Sep 2018 09:31:58 +0100 Subject: [PATCH] drm/i915/selftests: Smoketest preemption MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Very light stress test to bombard the submission backends with a large stream with requests of randomly assigned priorities. Preemption will be occasionally requested, but unlikely to ever succeed! (Although we may build a long queue of requests and so may trigger an attempt to inject a preempt context, as we emit no batch, the arbitration window is limited to between requests inside the ringbuffer. The likelihood of actually causing a preemption event is therefore very small. A later variant should try to improve the likelihood of preemption events!) v2: Include a second pattern with more frequent preemption Signed-off-by: Chris Wilson Cc: Michał Winiarski Cc: Tvrtko Ursulin Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20180925083205.2229-1-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/selftests/intel_lrc.c | 137 +++++++++++++++++++++++++++++ 1 file changed, 137 insertions(+) diff --git a/drivers/gpu/drm/i915/selftests/intel_lrc.c b/drivers/gpu/drm/i915/selftests/intel_lrc.c index 1aea7a8..3a474bb 100644 --- a/drivers/gpu/drm/i915/selftests/intel_lrc.c +++ b/drivers/gpu/drm/i915/selftests/intel_lrc.c @@ -6,6 +6,7 @@ #include "../i915_selftest.h" #include "igt_flush_test.h" +#include "i915_random.h" #include "mock_context.h" @@ -573,6 +574,141 @@ err_unlock: return err; } +static int random_range(struct rnd_state *rnd, int min, int max) +{ + return i915_prandom_u32_max_state(max - min, rnd) + min; +} + +static int random_priority(struct rnd_state *rnd) +{ + return random_range(rnd, I915_PRIORITY_MIN, I915_PRIORITY_MAX); +} + +struct preempt_smoke { + struct drm_i915_private *i915; + struct i915_gem_context **contexts; + unsigned int ncontext; + struct rnd_state prng; +}; + +static struct i915_gem_context *smoke_context(struct preempt_smoke *smoke) +{ + return smoke->contexts[i915_prandom_u32_max_state(smoke->ncontext, + &smoke->prng)]; +} + +static int smoke_crescendo(struct preempt_smoke *smoke) +{ + struct intel_engine_cs *engine; + enum intel_engine_id id; + unsigned long count; + + count = 0; + for_each_engine(engine, smoke->i915, id) { + IGT_TIMEOUT(end_time); + + do { + struct i915_gem_context *ctx = smoke_context(smoke); + struct i915_request *rq; + + ctx->sched.priority = count % I915_PRIORITY_MAX; + + rq = i915_request_alloc(engine, ctx); + if (IS_ERR(rq)) + return PTR_ERR(rq); + + i915_request_add(rq); + count++; + } while (!__igt_timeout(end_time, NULL)); + } + + pr_info("Submitted %lu crescendo requests across %d engines and %d contexts\n", + count, INTEL_INFO(smoke->i915)->num_rings, smoke->ncontext); + return 0; +} + +static int smoke_random(struct preempt_smoke *smoke) +{ + struct intel_engine_cs *engine; + enum intel_engine_id id; + IGT_TIMEOUT(end_time); + unsigned long count; + + count = 0; + do { + for_each_engine(engine, smoke->i915, id) { + struct i915_gem_context *ctx = smoke_context(smoke); + struct i915_request *rq; + + ctx->sched.priority = random_priority(&smoke->prng); + + rq = i915_request_alloc(engine, ctx); + if (IS_ERR(rq)) + return PTR_ERR(rq); + + i915_request_add(rq); + count++; + } + } while (!__igt_timeout(end_time, NULL)); + + pr_info("Submitted %lu random requests across %d engines and %d contexts\n", + count, INTEL_INFO(smoke->i915)->num_rings, smoke->ncontext); + return 0; +} + +static int live_preempt_smoke(void *arg) +{ + struct preempt_smoke smoke = { + .i915 = arg, + .prng = I915_RND_STATE_INITIALIZER(i915_selftest.random_seed), + .ncontext = 1024, + }; + int err = -ENOMEM; + int n; + + if (!HAS_LOGICAL_RING_PREEMPTION(smoke.i915)) + return 0; + + smoke.contexts = kmalloc_array(smoke.ncontext, + sizeof(*smoke.contexts), + GFP_KERNEL); + if (!smoke.contexts) + return -ENOMEM; + + mutex_lock(&smoke.i915->drm.struct_mutex); + intel_runtime_pm_get(smoke.i915); + + for (n = 0; n < smoke.ncontext; n++) { + smoke.contexts[n] = kernel_context(smoke.i915); + if (!smoke.contexts[n]) + goto err_ctx; + } + + err = smoke_crescendo(&smoke); + if (err) + goto err_ctx; + + err = smoke_random(&smoke); + if (err) + goto err_ctx; + +err_ctx: + if (igt_flush_test(smoke.i915, I915_WAIT_LOCKED)) + err = -EIO; + + for (n = 0; n < smoke.ncontext; n++) { + if (!smoke.contexts[n]) + break; + kernel_context_close(smoke.contexts[n]); + } + + intel_runtime_pm_put(smoke.i915); + mutex_unlock(&smoke.i915->drm.struct_mutex); + kfree(smoke.contexts); + + return err; +} + int intel_execlists_live_selftests(struct drm_i915_private *i915) { static const struct i915_subtest tests[] = { @@ -580,6 +716,7 @@ int intel_execlists_live_selftests(struct drm_i915_private *i915) SUBTEST(live_preempt), SUBTEST(live_late_preempt), SUBTEST(live_preempt_hang), + SUBTEST(live_preempt_smoke), }; if (!HAS_EXECLISTS(i915)) -- 2.7.4