From 2d19a71ce68f34e4f3570ca98d42912fbbd31f6c Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 14 Nov 2019 22:57:35 +0000 Subject: [PATCH] drm/i915/selftests: Exercise long preemption chains Verify that we can execute a long chain of dependent requests from userspace, each one slightly more important than the last. Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Reviewed-by: Tvrtko Ursulin Link: https://patchwork.freedesktop.org/patch/msgid/20191114225736.616885-4-chris@chris-wilson.co.uk --- drivers/gpu/drm/i915/gt/selftest_lrc.c | 196 +++++++++++++++++++++++++ 1 file changed, 196 insertions(+) diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c index d1ed3c0f851c..16ebe4d2308e 100644 --- a/drivers/gpu/drm/i915/gt/selftest_lrc.c +++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c @@ -1915,6 +1915,201 @@ err_wedged: goto err_client_lo; } +static int create_gang(struct intel_engine_cs *engine, + struct i915_request **prev) +{ + struct drm_i915_gem_object *obj; + struct intel_context *ce; + struct i915_request *rq; + struct i915_vma *vma; + u32 *cs; + int err; + + ce = intel_context_create(engine->kernel_context->gem_context, engine); + if (IS_ERR(ce)) + return PTR_ERR(ce); + + obj = i915_gem_object_create_internal(engine->i915, 4096); + if (IS_ERR(obj)) { + err = PTR_ERR(obj); + goto err_ce; + } + + vma = i915_vma_instance(obj, ce->vm, NULL); + if (IS_ERR(vma)) { + err = PTR_ERR(vma); + goto err_obj; + } + + err = i915_vma_pin(vma, 0, 0, PIN_USER); + if (err) + goto err_obj; + + cs = i915_gem_object_pin_map(obj, I915_MAP_WC); + if (IS_ERR(cs)) + goto err_obj; + + /* Semaphore target: spin until zero */ + *cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE; + + *cs++ = MI_SEMAPHORE_WAIT | + MI_SEMAPHORE_POLL | + MI_SEMAPHORE_SAD_EQ_SDD; + *cs++ = 0; + *cs++ = lower_32_bits(vma->node.start); + *cs++ = upper_32_bits(vma->node.start); + + if (*prev) { + u64 offset = (*prev)->batch->node.start; + + /* Terminate the spinner in the next lower priority batch. */ + *cs++ = MI_STORE_DWORD_IMM_GEN4; + *cs++ = lower_32_bits(offset); + *cs++ = upper_32_bits(offset); + *cs++ = 0; + } + + *cs++ = MI_BATCH_BUFFER_END; + i915_gem_object_flush_map(obj); + i915_gem_object_unpin_map(obj); + + rq = intel_context_create_request(ce); + if (IS_ERR(rq)) + goto err_obj; + + rq->batch = vma; + i915_request_get(rq); + + i915_vma_lock(vma); + err = i915_request_await_object(rq, vma->obj, false); + if (!err) + err = i915_vma_move_to_active(vma, rq, 0); + if (!err) + err = rq->engine->emit_bb_start(rq, + vma->node.start, + PAGE_SIZE, 0); + i915_vma_unlock(vma); + i915_request_add(rq); + if (err) + goto err_rq; + + i915_gem_object_put(obj); + intel_context_put(ce); + + rq->client_link.next = &(*prev)->client_link; + *prev = rq; + return 0; + +err_rq: + i915_request_put(rq); +err_obj: + i915_gem_object_put(obj); +err_ce: + intel_context_put(ce); + return err; +} + +static int live_preempt_gang(void *arg) +{ + struct intel_gt *gt = arg; + struct intel_engine_cs *engine; + enum intel_engine_id id; + + if (!HAS_LOGICAL_RING_PREEMPTION(gt->i915)) + return 0; + + /* + * Build as long a chain of preempters as we can, with each + * request higher priority than the last. Once we are ready, we release + * the last batch which then precolates down the chain, each releasing + * the next oldest in turn. The intent is to simply push as hard as we + * can with the number of preemptions, trying to exceed narrow HW + * limits. At a minimum, we insist that we can sort all the user + * high priority levels into execution order. + */ + + for_each_engine(engine, gt, id) { + struct i915_request *rq = NULL; + struct igt_live_test t; + IGT_TIMEOUT(end_time); + int prio = 0; + int err = 0; + u32 *cs; + + if (!intel_engine_has_preemption(engine)) + continue; + + if (igt_live_test_begin(&t, gt->i915, __func__, engine->name)) + return -EIO; + + do { + struct i915_sched_attr attr = { + .priority = I915_USER_PRIORITY(prio++), + }; + + err = create_gang(engine, &rq); + if (err) + break; + + /* Submit each spinner at increasing priority */ + engine->schedule(rq, &attr); + + if (prio <= I915_PRIORITY_MAX) + continue; + + if (prio > (INT_MAX >> I915_USER_PRIORITY_SHIFT)) + break; + + if (__igt_timeout(end_time, NULL)) + break; + } while (1); + pr_debug("%s: Preempt chain of %d requests\n", + engine->name, prio); + + /* + * Such that the last spinner is the highest priority and + * should execute first. When that spinner completes, + * it will terminate the next lowest spinner until there + * are no more spinners and the gang is complete. + */ + cs = i915_gem_object_pin_map(rq->batch->obj, I915_MAP_WC); + if (!IS_ERR(cs)) { + *cs = 0; + i915_gem_object_unpin_map(rq->batch->obj); + } else { + err = PTR_ERR(cs); + intel_gt_set_wedged(gt); + } + + while (rq) { /* wait for each rq from highest to lowest prio */ + struct i915_request *n = + list_next_entry(rq, client_link); + + if (err == 0 && i915_request_wait(rq, 0, HZ / 5) < 0) { + struct drm_printer p = + drm_info_printer(engine->i915->drm.dev); + + pr_err("Failed to flush chain of %d requests, at %d\n", + prio, rq_prio(rq) >> I915_USER_PRIORITY_SHIFT); + intel_engine_dump(engine, &p, + "%s\n", engine->name); + + err = -ETIME; + } + + i915_request_put(rq); + rq = n; + } + + if (igt_live_test_end(&t)) + err = -EIO; + if (err) + return err; + } + + return 0; +} + static int live_preempt_hang(void *arg) { struct intel_gt *gt = arg; @@ -3028,6 +3223,7 @@ int intel_execlists_live_selftests(struct drm_i915_private *i915) SUBTEST(live_suppress_self_preempt), SUBTEST(live_suppress_wait_preempt), SUBTEST(live_chain_preempt), + SUBTEST(live_preempt_gang), SUBTEST(live_preempt_hang), SUBTEST(live_preempt_timeout), SUBTEST(live_preempt_smoke), -- 2.20.1