From patchwork Wed Jun 27 20:13:03 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10492595 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 F299760386 for ; Wed, 27 Jun 2018 20:13:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 0693B29F95 for ; Wed, 27 Jun 2018 20:13:29 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EC36229FAF; Wed, 27 Jun 2018 20:13:28 +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=-5.2 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, 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 8C38A29F95 for ; Wed, 27 Jun 2018 20:13:28 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id EB9466EB7F; Wed, 27 Jun 2018 20:13:27 +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 8BF936EB78 for ; Wed, 27 Jun 2018 20:13:18 +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 12180033-1500050 for multiple; Wed, 27 Jun 2018 21:13:10 +0100 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Wed, 27 Jun 2018 21:13:09 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Wed, 27 Jun 2018 21:13:03 +0100 Message-Id: <20180627201304.15817-3-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180627201304.15817-1-chris@chris-wilson.co.uk> References: <20180627201304.15817-1-chris@chris-wilson.co.uk> X-Originating-IP: 78.156.65.138 X-Country: code=GB country="United Kingdom" ip=78.156.65.138 Subject: [Intel-gfx] [PATCH 3/4] drm/i915: Move the irq_counter inside the spinlock 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: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP Rather than have multiple locked instructions inside the notify_ring() irq handler, move them inside the spinlock and reduce their intrinsic locking. Signed-off-by: Chris Wilson Reviewed-by: Mika Kuoppala --- drivers/gpu/drm/i915/i915_irq.c | 4 ++-- drivers/gpu/drm/i915/i915_request.c | 4 ++-- drivers/gpu/drm/i915/intel_breadcrumbs.c | 11 +++++++---- drivers/gpu/drm/i915/intel_ringbuffer.h | 2 +- 4 files changed, 12 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 55aba89adfb1..6adeaac48ea9 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -1153,8 +1153,6 @@ static void notify_ring(struct intel_engine_cs *engine) if (unlikely(!engine->breadcrumbs.irq_armed)) return; - atomic_inc(&engine->irq_count); - rcu_read_lock(); spin_lock(&engine->breadcrumbs.irq_lock); @@ -1189,6 +1187,8 @@ static void notify_ring(struct intel_engine_cs *engine) tsk = wait->tsk; } } + + engine->breadcrumbs.irq_count++; } else { if (engine->breadcrumbs.irq_armed) __intel_engine_disarm_breadcrumbs(engine); diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index e1dbb544046f..39b296878ba2 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -1196,7 +1196,7 @@ static bool __i915_spin_request(const struct i915_request *rq, * takes to sleep on a request, on the order of a microsecond. */ - irq = atomic_read(&engine->irq_count); + irq = READ_ONCE(engine->breadcrumbs.irq_count); timeout_us += local_clock_us(&cpu); do { if (i915_seqno_passed(intel_engine_get_seqno(engine), seqno)) @@ -1208,7 +1208,7 @@ static bool __i915_spin_request(const struct i915_request *rq, * assume we won't see one in the near future but require * the engine->seqno_barrier() to fixup coherency. */ - if (atomic_read(&engine->irq_count) != irq) + if (READ_ONCE(engine->breadcrumbs.irq_count) != irq) break; if (signal_pending_state(state, current)) diff --git a/drivers/gpu/drm/i915/intel_breadcrumbs.c b/drivers/gpu/drm/i915/intel_breadcrumbs.c index 86a987b8ac66..1db6ba7d926e 100644 --- a/drivers/gpu/drm/i915/intel_breadcrumbs.c +++ b/drivers/gpu/drm/i915/intel_breadcrumbs.c @@ -98,12 +98,14 @@ static void intel_breadcrumbs_hangcheck(struct timer_list *t) struct intel_engine_cs *engine = from_timer(engine, t, breadcrumbs.hangcheck); struct intel_breadcrumbs *b = &engine->breadcrumbs; + unsigned int irq_count; if (!b->irq_armed) return; - if (b->hangcheck_interrupts != atomic_read(&engine->irq_count)) { - b->hangcheck_interrupts = atomic_read(&engine->irq_count); + irq_count = READ_ONCE(b->irq_count); + if (b->hangcheck_interrupts != irq_count) { + b->hangcheck_interrupts = irq_count; mod_timer(&b->hangcheck, wait_timeout()); return; } @@ -272,13 +274,14 @@ static bool use_fake_irq(const struct intel_breadcrumbs *b) if (!test_bit(engine->id, &engine->i915->gpu_error.missed_irq_rings)) return false; - /* Only start with the heavy weight fake irq timer if we have not + /* + * Only start with the heavy weight fake irq timer if we have not * seen any interrupts since enabling it the first time. If the * interrupts are still arriving, it means we made a mistake in our * engine->seqno_barrier(), a timing error that should be transient * and unlikely to reoccur. */ - return atomic_read(&engine->irq_count) == b->hangcheck_interrupts; + return READ_ONCE(b->irq_count) == b->hangcheck_interrupts; } static void enable_fake_irq(struct intel_breadcrumbs *b) diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h index a0bc7a8222b4..44ac90ec540c 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.h +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h @@ -345,7 +345,6 @@ struct intel_engine_cs { struct drm_i915_gem_object *default_state; void *pinned_default_state; - atomic_t irq_count; unsigned long irq_posted; #define ENGINE_IRQ_BREADCRUMB 0 #define ENGINE_IRQ_EXECLIST 1 @@ -380,6 +379,7 @@ struct intel_engine_cs { unsigned int hangcheck_interrupts; unsigned int irq_enabled; + unsigned int irq_count; bool irq_armed : 1; I915_SELFTEST_DECLARE(bool mock : 1);