From patchwork Thu Jul 2 09:52:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11638399 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 85FEF6C1 for ; Thu, 2 Jul 2020 09:52:26 +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 6E6402084C for ; Thu, 2 Jul 2020 09:52:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6E6402084C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=chris-wilson.co.uk 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 3C8C16E05D; Thu, 2 Jul 2020 09:52:24 +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 1C6166E05D for ; Thu, 2 Jul 2020 09:52:22 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from build.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 21686398-1500050 for ; Thu, 02 Jul 2020 10:52:17 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Thu, 2 Jul 2020 10:52:18 +0100 Message-Id: <20200702095219.963-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Subject: [Intel-gfx] [CI 1/2] drm/i915/gt: Harden the heartbeat against a stuck driver 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: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" If the driver gets stuck holding the kernel timeline, we cannot issue a heartbeat and so fail to discover that the driver is indeed stuck and do not issue a GPU reset (which would hopefully unstick the driver!). Switch to using a trylock so that we can query if the heartbeat's timeline mutex is locked elsewhere, and then use the timer to probe if it remains stuck at the same spot for consecutive heartbeats, indicating that the mutex has not been released and the engine has not progressed. Signed-off-by: Chris Wilson Reviewed-by: Mika Kuoppala --- drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c | 14 ++++++++++++-- drivers/gpu/drm/i915/gt/intel_engine_types.h | 1 + 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c index 8db7e93abde5..1c6c6692dd17 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c +++ b/drivers/gpu/drm/i915/gt/intel_engine_heartbeat.c @@ -65,6 +65,7 @@ static void heartbeat(struct work_struct *wrk) container_of(wrk, typeof(*engine), heartbeat.work.work); struct intel_context *ce = engine->kernel_context; struct i915_request *rq; + unsigned long serial; /* Just in case everything has gone horribly wrong, give it a kick */ intel_engine_flush_submission(engine); @@ -122,10 +123,19 @@ static void heartbeat(struct work_struct *wrk) goto out; } - if (engine->wakeref_serial == engine->serial) + serial = READ_ONCE(engine->serial); + if (engine->wakeref_serial == serial) goto out; - mutex_lock(&ce->timeline->mutex); + if (!mutex_trylock(&ce->timeline->mutex)) { + /* Unable to lock the kernel timeline, is the engine stuck? */ + if (xchg(&engine->heartbeat.blocked, serial) == serial) + intel_gt_handle_error(engine->gt, engine->mask, + I915_ERROR_CAPTURE, + "no heartbeat on %s", + engine->name); + goto out; + } intel_context_enter(ce); rq = __i915_request_create(ce, GFP_NOWAIT | __GFP_NOWARN); diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h index 073c3769e8cc..490af81bd6f3 100644 --- a/drivers/gpu/drm/i915/gt/intel_engine_types.h +++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h @@ -348,6 +348,7 @@ struct intel_engine_cs { struct { struct delayed_work work; struct i915_request *systole; + unsigned long blocked; } heartbeat; unsigned long serial;