From patchwork Fri Mar 30 10:39:12 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10317603 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 6C0D760212 for ; Fri, 30 Mar 2018 10:40:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5CAFE286C8 for ; Fri, 30 Mar 2018 10:40:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 510B6286EC; Fri, 30 Mar 2018 10:40:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9E26B286C8 for ; Fri, 30 Mar 2018 10:40:16 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7CE556E403; Fri, 30 Mar 2018 10:40:14 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8FEFE6E862 for ; Fri, 30 Mar 2018 10:40:01 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from haswell.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 11213830-1500050 for multiple; Fri, 30 Mar 2018 11:39:51 +0100 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Fri, 30 Mar 2018 11:39:50 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Fri, 30 Mar 2018 11:39:12 +0100 Message-Id: <20180330103915.23018-15-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.16.3 In-Reply-To: <20180330103915.23018-1-chris@chris-wilson.co.uk> References: <20180330103915.23018-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 X-Originating-IP: 78.156.65.138 X-Country: code=GB country="United Kingdom" ip=78.156.65.138 Subject: [Intel-gfx] [PATCH 14/17] drm/i915/execlists: Try preempt-reset from softirq context X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP When circumstances allow, trying resetting the engine directly from the preemption timeout handler. As this is softirq context, we have to be careful both not to sleep and not to spin on anything we may be interrupting (e.g. the submission tasklet). Signed-off-by: Chris Wilson Cc: Mika Kuoppala Cc: Michał Winiarski CC: Michel Thierry Cc: Jeff McGee Cc: Tvrtko Ursulin --- drivers/gpu/drm/i915/intel_lrc.c | 31 +++++++- drivers/gpu/drm/i915/selftests/intel_lrc.c | 121 +++++++++++++++++++++++++++++ 2 files changed, 151 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index cb11b14cd93c..dfbf0913f14e 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -549,6 +549,33 @@ static void inject_preempt_context(struct intel_engine_cs *engine) execlists_set_active(execlists, EXECLISTS_ACTIVE_PREEMPT); } +static int try_preempt_reset(struct intel_engine_execlists *execlists) +{ + struct intel_engine_cs *engine = + container_of(execlists, typeof(*engine), execlists); + int err = -EBUSY; + + if (!test_bit(ENGINE_IRQ_EXECLIST, &engine->irq_posted) && + tasklet_trylock(&execlists->tasklet)) { + unsigned long *lock = &engine->i915->gpu_error.flags; + unsigned int bit = I915_RESET_ENGINE + engine->id; + + if (!test_and_set_bit(bit, lock)) { + tasklet_disable_nosync(&engine->execlists.tasklet); + err = i915_reset_engine(engine, + "preemption time out"); + tasklet_enable(&engine->execlists.tasklet); + + clear_bit(bit, lock); + wake_up_bit(lock, bit); + } + + tasklet_unlock(&execlists->tasklet); + } + + return err; +} + static enum hrtimer_restart preempt_timeout(struct hrtimer *hrtimer) { struct intel_engine_execlists *execlists = @@ -562,7 +589,9 @@ static enum hrtimer_restart preempt_timeout(struct hrtimer *hrtimer) if (!execlists_is_active(execlists, EXECLISTS_ACTIVE_PREEMPT_TIMEOUT)) return HRTIMER_NORESTART; - queue_work(system_highpri_wq, &execlists->preempt_reset); + if (try_preempt_reset(execlists)) + queue_work(system_highpri_wq, &execlists->preempt_reset); + return HRTIMER_NORESTART; } diff --git a/drivers/gpu/drm/i915/selftests/intel_lrc.c b/drivers/gpu/drm/i915/selftests/intel_lrc.c index b9c9c1d26cc1..626acf46f65e 100644 --- a/drivers/gpu/drm/i915/selftests/intel_lrc.c +++ b/drivers/gpu/drm/i915/selftests/intel_lrc.c @@ -553,6 +553,126 @@ static int live_preempt_timeout(void *arg) return err; } +static void __softirq_begin(void) +{ + local_bh_disable(); +} + +static void __softirq_end(void) +{ + local_bh_enable(); +} + +static void __hardirq_begin(void) +{ + local_irq_disable(); +} + +static void __hardirq_end(void) +{ + local_irq_enable(); +} + +static int live_preempt_reset(void *arg) +{ + struct drm_i915_private *i915 = arg; + struct intel_engine_cs *engine; + struct i915_gem_context *ctx; + enum intel_engine_id id; + struct spinner spin; + int err = -ENOMEM; + + if (!HAS_LOGICAL_RING_PREEMPTION(i915)) + return 0; + + mutex_lock(&i915->drm.struct_mutex); + + if (spinner_init(&spin, i915)) + goto err_unlock; + + ctx= kernel_context(i915); + if (!ctx) + goto err_spin; + + for_each_engine(engine, i915, id) { + static const struct { + const char *name; + void (*critical_section_begin)(void); + void (*critical_section_end)(void); + } phases[] = { + { "softirq", __softirq_begin, __softirq_end }, + { "hardirq", __hardirq_begin, __hardirq_end }, + { } + }; + const typeof(*phases) *p; + + for (p = phases; p->name; p++) { + struct i915_request *rq; + + rq = spinner_create_request(&spin, ctx, engine, + MI_NOOP); + if (IS_ERR(rq)) { + err = PTR_ERR(rq); + goto err_ctx; + } + + i915_request_add(rq); + if (!wait_for_spinner(&spin, rq)) { + i915_gem_set_wedged(i915); + err = -EIO; + goto err_ctx; + } + + /* Flush to give try_preempt_reset a chance */ + do { + tasklet_schedule(&engine->execlists.tasklet); + usleep_range(100, 1000); + tasklet_kill(&engine->execlists.tasklet); + } while (test_bit(ENGINE_IRQ_EXECLIST, + &engine->irq_posted)); + GEM_BUG_ON(i915_request_completed(rq)); + + GEM_TRACE("%s triggering %s reset\n", + engine->name, p->name); + p->critical_section_begin(); + err = try_preempt_reset(&engine->execlists); + p->critical_section_end(); + if (err) { + pr_err("Preempt softirq reset failed on %s, irq_posted? %d, tasklet state %lx\n", + engine->name, + test_bit(ENGINE_IRQ_EXECLIST, + &engine->irq_posted), + engine->execlists.tasklet.state); + i915_gem_set_wedged(i915); + goto err_ctx; + } + + /* + * In such a simple case as above; triggering a reset + * allows us to save and restore the hog nearly + * perfectly... + */ + GEM_BUG_ON(i915_request_completed(rq)); + spinner_end(&spin); + + if (flush_test(i915, I915_WAIT_LOCKED)) { + err = -EIO; + goto err_ctx; + } + } + } + + err = 0; +err_ctx: + kernel_context_close(ctx); +err_spin: + spinner_fini(&spin); +err_unlock: + flush_test(i915, I915_WAIT_LOCKED); + mutex_unlock(&i915->drm.struct_mutex); + return err; +} + int intel_execlists_live_selftests(struct drm_i915_private *i915) { static const struct i915_subtest tests[] = { @@ -560,6 +680,7 @@ int intel_execlists_live_selftests(struct drm_i915_private *i915) SUBTEST(live_preempt), SUBTEST(live_late_preempt), SUBTEST(live_preempt_timeout), + SUBTEST(live_preempt_reset), }; return i915_subtests(tests, i915); }