From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, HK_RANDOM_FROM,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AB36DC33C9E for ; Tue, 14 Jan 2020 18:33:12 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8EF53222C4 for ; Tue, 14 Jan 2020 18:33:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8EF53222C4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1BFC56E434; Tue, 14 Jan 2020 18:33:12 +0000 (UTC) Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by gabe.freedesktop.org (Postfix) with ESMTPS id 09BEE6E434 for ; Tue, 14 Jan 2020 18:33:10 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 14 Jan 2020 10:33:10 -0800 X-IronPort-AV: E=Sophos;i="5.70,319,1574150400"; d="scan'208";a="213427492" Received: from mdanino-mobl1.ger.corp.intel.com (HELO [10.252.23.174]) ([10.252.23.174]) by orsmga007-auth.jf.intel.com with ESMTP/TLS/AES256-SHA; 14 Jan 2020 10:33:09 -0800 To: Chris Wilson , intel-gfx@lists.freedesktop.org References: <20200113104442.1753973-1-chris@chris-wilson.co.uk> <20200113104442.1753973-3-chris@chris-wilson.co.uk> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc Message-ID: <40d5588a-9c47-495b-a7d2-b8adacc50ef2@linux.intel.com> Date: Tue, 14 Jan 2020 18:33:07 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20200113104442.1753973-3-chris@chris-wilson.co.uk> Content-Language: en-US Subject: Re: [Intel-gfx] [PATCH 3/4] drm/i915/gt: Allow temporary suspension of inflight requests X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 13/01/2020 10:44, Chris Wilson wrote: > In order to support out-of-line error capture, we need to remove the > active request from HW and put it to one side while a worker compresses > and stores all the details associated with that request. (As that > compression may take an arbitrary user-controlled amount of time, we > want to let the engine continue running on other workloads while the > hanging request is dumped.) Not only do we need to remove the active > request, but we also have to remove its context and all requests that > were dependent on it (both in flight, queued and future submission). > > Finally once the capture is complete, we need to be able to resubmit the > request and its dependents and allow them to execute. > > References: https://gitlab.freedesktop.org/drm/intel/issues/738 > Signed-off-by: Chris Wilson > Cc: Tvrtko Ursulin > --- > drivers/gpu/drm/i915/gt/intel_engine_cs.c | 1 + > drivers/gpu/drm/i915/gt/intel_engine_types.h | 1 + > drivers/gpu/drm/i915/gt/intel_lrc.c | 109 ++++++++++++++++++- > drivers/gpu/drm/i915/gt/selftest_lrc.c | 103 ++++++++++++++++++ > drivers/gpu/drm/i915/i915_request.h | 22 ++++ > 5 files changed, 231 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c > index f451ef376548..c296aaf381e7 100644 > --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c > +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c > @@ -671,6 +671,7 @@ void > intel_engine_init_active(struct intel_engine_cs *engine, unsigned int subclass) > { > INIT_LIST_HEAD(&engine->active.requests); > + INIT_LIST_HEAD(&engine->active.hold); > > spin_lock_init(&engine->active.lock); > lockdep_set_subclass(&engine->active.lock, subclass); > diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h > index 00287515e7af..6f4f9912a364 100644 > --- a/drivers/gpu/drm/i915/gt/intel_engine_types.h > +++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h > @@ -295,6 +295,7 @@ struct intel_engine_cs { > struct { > spinlock_t lock; > struct list_head requests; > + struct list_head hold; > } active; > > struct llist_head barrier_tasks; > diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c > index 685659f079a2..e0347e05e577 100644 > --- a/drivers/gpu/drm/i915/gt/intel_lrc.c > +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c > @@ -2355,6 +2355,77 @@ static void __execlists_submission_tasklet(struct intel_engine_cs *const engine) > } > } > > +static void __execlists_hold(struct i915_request *rq) > +{ > + struct i915_dependency *p; > + > + if (!i915_request_completed(rq)) { > + RQ_TRACE(rq, "on hold\n"); > + if (i915_request_is_active(rq)) > + __i915_request_unsubmit(rq); > + clear_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags); > + list_move_tail(&rq->sched.link, &rq->engine->active.hold); > + i915_request_set_hold(rq); > + } > + > + list_for_each_entry(p, &rq->sched.waiters_list, wait_link) { > + struct i915_request *w = > + container_of(p->waiter, typeof(*w), sched); > + > + /* Leave semaphores spinning on the other engines */ > + if (w->engine != rq->engine) > + continue; > + > + __execlists_hold(w); Seems like easy stack overflow attach due recursion. > + } > +} > + > +__maybe_unused > +static void execlists_hold(struct intel_engine_cs *engine, > + struct i915_request *rq) > +{ > + spin_lock_irq(&engine->active.lock); > + __execlists_hold(rq); Can this get called with rq->engine != engine? > + spin_unlock_irq(&engine->active.lock); > +} > + > +static void __execlists_unhold(struct i915_request *rq) > +{ > + struct i915_dependency *p; > + > + if (!i915_request_has_hold(rq)) > + return; > + > + i915_request_clear_hold(rq); > + list_move_tail(&rq->sched.link, > + i915_sched_lookup_priolist(rq->engine, rq_prio(rq))); > + set_bit(I915_FENCE_FLAG_PQUEUE, &rq->fence.flags); > + RQ_TRACE(rq, "hold release\n"); > + > + list_for_each_entry(p, &rq->sched.waiters_list, wait_link) { > + struct i915_request *w = > + container_of(p->waiter, typeof(*w), sched); > + > + if (w->engine != rq->engine) > + continue; > + > + __execlists_unhold(w); > + } > +} > + > +__maybe_unused > +static void execlists_unhold(struct intel_engine_cs *engine, > + struct i915_request *rq) > +{ > + spin_lock_irq(&engine->active.lock); > + __execlists_unhold(rq); > + if (rq_prio(rq) > engine->execlists.queue_priority_hint) { > + engine->execlists.queue_priority_hint = rq_prio(rq); > + tasklet_hi_schedule(&engine->execlists.tasklet); > + } > + spin_unlock_irq(&engine->active.lock); > +} > + > static noinline void preempt_reset(struct intel_engine_cs *engine) > { > const unsigned int bit = I915_RESET_ENGINE + engine->id; > @@ -2466,6 +2537,29 @@ static void submit_queue(struct intel_engine_cs *engine, > __submit_queue_imm(engine); > } > > +static bool hold_request(const struct i915_request *rq) > +{ > + struct i915_dependency *p; > + > + list_for_each_entry(p, &rq->sched.signalers_list, signal_link) { > + const struct i915_request *s = > + container_of(p->signaler, typeof(*s), sched); > + > + if (s->engine != rq->engine) > + continue; > + > + return i915_request_has_hold(s); > + } > + > + return false; > +} I am not sure what question this function is answering. Needs a comment or a better name I think. > + > +static bool on_hold(const struct intel_engine_cs *engine, > + const struct i915_request *rq) > +{ > + return !list_empty(&engine->active.hold) && hold_request(rq); When is engine != rq->engine? Secondly, first part of the conditional seems to be asking whether this engine has any requests on hold. Second part whether a particular rq has a dependency on hold, on the same engine as rq->engine. Needs to be explained with a comment. Is the first check just an optimisation? > +} > + > static void execlists_submit_request(struct i915_request *request) > { > struct intel_engine_cs *engine = request->engine; > @@ -2474,13 +2568,18 @@ static void execlists_submit_request(struct i915_request *request) > /* Will be called from irq-context when using foreign fences. */ > spin_lock_irqsave(&engine->active.lock, flags); > > - queue_request(engine, &request->sched, rq_prio(request)); > - set_bit(I915_FENCE_FLAG_PQUEUE, &request->fence.flags); > + if (unlikely(on_hold(engine, request))) { > + i915_request_set_hold(request); > + list_add_tail(&request->sched.link, &engine->active.hold); Or explained here. But in general this part is for when new dependencies of a held request become runnable? Regards, Tvrtko > + } else { > + queue_request(engine, &request->sched, rq_prio(request)); > + set_bit(I915_FENCE_FLAG_PQUEUE, &request->fence.flags); > > - GEM_BUG_ON(RB_EMPTY_ROOT(&engine->execlists.queue.rb_root)); > - GEM_BUG_ON(list_empty(&request->sched.link)); > + GEM_BUG_ON(RB_EMPTY_ROOT(&engine->execlists.queue.rb_root)); > + GEM_BUG_ON(list_empty(&request->sched.link)); > > - submit_queue(engine, request); > + submit_queue(engine, request); > + } > > spin_unlock_irqrestore(&engine->active.lock, flags); > } > diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c > index 15cda024e3e4..78501d79c0ea 100644 > --- a/drivers/gpu/drm/i915/gt/selftest_lrc.c > +++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c > @@ -285,6 +285,108 @@ static int live_unlite_preempt(void *arg) > return live_unlite_restore(arg, I915_USER_PRIORITY(I915_PRIORITY_MAX)); > } > > +static int live_hold_reset(void *arg) > +{ > + struct intel_gt *gt = arg; > + struct intel_engine_cs *engine; > + enum intel_engine_id id; > + struct igt_spinner spin; > + int err = 0; > + > + /* > + * In order to support offline error capture for fast preempt reset, > + * we need to decouple the guilty request and ensure that it and its > + * descendents are not executed while the capture is in progress. > + */ > + > + if (!intel_has_reset_engine(gt)) > + return 0; > + > + if (igt_spinner_init(&spin, gt)) > + return -ENOMEM; > + > + for_each_engine(engine, gt, id) { > + struct intel_context *ce; > + unsigned long heartbeat; > + struct i915_request *rq; > + > + ce = intel_context_create(engine); > + if (IS_ERR(ce)) { > + err = PTR_ERR(ce); > + break; > + } > + > + engine_heartbeat_disable(engine, &heartbeat); > + > + rq = igt_spinner_create_request(&spin, ce, MI_ARB_CHECK); > + if (IS_ERR(rq)) { > + err = PTR_ERR(rq); > + goto out; > + } > + i915_request_add(rq); > + > + if (!igt_wait_for_spinner(&spin, rq)) { > + intel_gt_set_wedged(gt); > + err = -ETIME; > + goto out; > + } > + > + /* We have our request executing, now remove it and reset */ > + > + if (test_and_set_bit(I915_RESET_ENGINE + id, > + >->reset.flags)) { > + spin_unlock_irq(&engine->active.lock); > + intel_gt_set_wedged(gt); > + err = -EBUSY; > + goto out; > + } > + tasklet_disable(&engine->execlists.tasklet); > + > + engine->execlists.tasklet.func(engine->execlists.tasklet.data); > + GEM_BUG_ON(execlists_active(&engine->execlists) != rq); > + > + execlists_hold(engine, rq); > + GEM_BUG_ON(!i915_request_has_hold(rq)); > + > + intel_engine_reset(engine, NULL); > + GEM_BUG_ON(rq->fence.error != -EIO); > + > + tasklet_enable(&engine->execlists.tasklet); > + clear_and_wake_up_bit(I915_RESET_ENGINE + id, > + >->reset.flags); > + > + /* Check that we do not resubmit the held request */ > + i915_request_get(rq); > + if (!i915_request_wait(rq, 0, HZ / 5)) { > + pr_err("%s: on hold request completed!\n", > + engine->name); > + i915_request_put(rq); > + err = -EIO; > + goto out; > + } > + GEM_BUG_ON(!i915_request_has_hold(rq)); > + > + /* But is resubmitted on release */ > + execlists_unhold(engine, rq); > + if (i915_request_wait(rq, 0, HZ / 5) < 0) { > + pr_err("%s: held request did not complete!\n", > + engine->name); > + intel_gt_set_wedged(gt); > + err = -ETIME; > + } > + i915_request_put(rq); > + > +out: > + engine_heartbeat_enable(engine, heartbeat); > + intel_context_put(ce); > + if (err) > + break; > + } > + > + igt_spinner_fini(&spin); > + return err; > +} > + > static int > emit_semaphore_chain(struct i915_request *rq, struct i915_vma *vma, int idx) > { > @@ -3315,6 +3417,7 @@ int intel_execlists_live_selftests(struct drm_i915_private *i915) > SUBTEST(live_sanitycheck), > SUBTEST(live_unlite_switch), > SUBTEST(live_unlite_preempt), > + SUBTEST(live_hold_reset), > SUBTEST(live_timeslice_preempt), > SUBTEST(live_timeslice_queue), > SUBTEST(live_busywait_preempt), > diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h > index f3e50ec989b8..2da8cfb3f3a1 100644 > --- a/drivers/gpu/drm/i915/i915_request.h > +++ b/drivers/gpu/drm/i915/i915_request.h > @@ -89,6 +89,13 @@ enum { > */ > I915_FENCE_FLAG_SIGNAL, > > + /* > + * I915_FENCE_FLAG_HOLD - this request is currently on hold > + * > + * This request has been suspended, pending an ongoing investigation. > + */ > + I915_FENCE_FLAG_HOLD, > + > /* > * I915_FENCE_FLAG_NOPREEMPT - this request should not be preempted > * > @@ -499,6 +506,21 @@ static inline bool i915_request_has_sentinel(const struct i915_request *rq) > return unlikely(test_bit(I915_FENCE_FLAG_SENTINEL, &rq->fence.flags)); > } > > +static inline bool i915_request_has_hold(const struct i915_request *rq) > +{ > + return unlikely(test_bit(I915_FENCE_FLAG_HOLD, &rq->fence.flags)); > +} > + > +static inline void i915_request_set_hold(struct i915_request *rq) > +{ > + set_bit(I915_FENCE_FLAG_HOLD, &rq->fence.flags); > +} > + > +static inline void i915_request_clear_hold(struct i915_request *rq) > +{ > + clear_bit(I915_FENCE_FLAG_HOLD, &rq->fence.flags); > +} > + > static inline struct intel_timeline * > i915_request_timeline(struct i915_request *rq) > { > _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx