From patchwork Wed Mar 28 21:18:56 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10314155 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 EB5E7600F6 for ; Wed, 28 Mar 2018 21:19:48 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DB68E29188 for ; Wed, 28 Mar 2018 21:19:48 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D009A2990A; Wed, 28 Mar 2018 21:19:48 +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 6EB2D29188 for ; Wed, 28 Mar 2018 21:19:48 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BF79B6E236; Wed, 28 Mar 2018 21:19:47 +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 E93B289E1A for ; Wed, 28 Mar 2018 21:19:34 +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 11193806-1500050 for multiple; Wed, 28 Mar 2018 22:19:30 +0100 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Wed, 28 Mar 2018 22:19:30 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Wed, 28 Mar 2018 22:18:56 +0100 Message-Id: <20180328211857.32457-15-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.16.3 In-Reply-To: <20180328211857.32457-1-chris@chris-wilson.co.uk> References: <20180328211857.32457-1-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 14/15] drm/i915: Use a preemption timeout to enforce interactivity 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 Use a liberal timeout of 20ms to ensure that the rendering for an interactive pageflip is started in a timely fashion, and that user interaction is not blocked by GPU, or CPU, hogs. This is at the cost of resetting whoever was blocking the preemption, likely leading to that context/process being banned from submitting future requests. Signed-off-by: Chris Wilson --- drivers/gpu/drm/i915/i915_drv.h | 3 ++- drivers/gpu/drm/i915/i915_gem.c | 18 ++++++++++-------- drivers/gpu/drm/i915/intel_display.c | 18 +++++++++++++++++- 3 files changed, 29 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 800230ba1c3b..87388feb973d 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -3150,8 +3150,9 @@ int i915_gem_object_wait(struct drm_i915_gem_object *obj, struct intel_rps_client *rps); int i915_gem_object_wait_priority(struct drm_i915_gem_object *obj, unsigned int flags, - int priority); + int priority, unsigned int timeout); #define I915_PRIORITY_DISPLAY I915_PRIORITY_MAX +#define I915_PREEMPTION_TIMEOUT_DISPLAY (20 * 1000 * 1000) /* 20 ms */ int __must_check i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj, bool write); diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index d43be56e927f..41622f17be2e 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -469,7 +469,8 @@ i915_gem_object_wait_reservation(struct reservation_object *resv, return timeout; } -static void __fence_set_priority(struct dma_fence *fence, int prio) +static void __fence_set_priority(struct dma_fence *fence, + int prio, unsigned int timeout) { struct i915_request *rq; struct intel_engine_cs *engine; @@ -482,11 +483,12 @@ static void __fence_set_priority(struct dma_fence *fence, int prio) rcu_read_lock(); if (engine->schedule) - engine->schedule(rq, prio, 0); + engine->schedule(rq, prio, timeout); rcu_read_unlock(); } -static void fence_set_priority(struct dma_fence *fence, int prio) +static void fence_set_priority(struct dma_fence *fence, + int prio, unsigned int timeout) { /* Recurse once into a fence-array */ if (dma_fence_is_array(fence)) { @@ -494,16 +496,16 @@ static void fence_set_priority(struct dma_fence *fence, int prio) int i; for (i = 0; i < array->num_fences; i++) - __fence_set_priority(array->fences[i], prio); + __fence_set_priority(array->fences[i], prio, timeout); } else { - __fence_set_priority(fence, prio); + __fence_set_priority(fence, prio, timeout); } } int i915_gem_object_wait_priority(struct drm_i915_gem_object *obj, unsigned int flags, - int prio) + int prio, unsigned int timeout) { struct dma_fence *excl; @@ -518,7 +520,7 @@ i915_gem_object_wait_priority(struct drm_i915_gem_object *obj, return ret; for (i = 0; i < count; i++) { - fence_set_priority(shared[i], prio); + fence_set_priority(shared[i], prio, timeout); dma_fence_put(shared[i]); } @@ -528,7 +530,7 @@ i915_gem_object_wait_priority(struct drm_i915_gem_object *obj, } if (excl) { - fence_set_priority(excl, prio); + fence_set_priority(excl, prio, timeout); dma_fence_put(excl); } return 0; diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 3acd75753a31..b7992a427e8d 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -12786,7 +12786,23 @@ intel_prepare_plane_fb(struct drm_plane *plane, ret = intel_plane_pin_fb(to_intel_plane_state(new_state)); - i915_gem_object_wait_priority(obj, 0, I915_PRIORITY_DISPLAY); + /* + * Reschedule our dependencies, and ensure we run within a timeout. + * + * Note that if the timeout is exceeded, then whoever was running that + * prevented us from acquiring the GPU is declared rogue and reset. An + * unresponsive process will then be banned in order to preserve + * interactivity. Since this can be seen as a bit heavy-handed, we + * select a timeout for when the dropped frames start to become a + * noticeable nuisance for the user (20 ms, i.e. preemption was blocked + * for more than a frame). Note, this is only a timeout for a delay in + * preempting the current request in order to run our dependency chain, + * our dependency chain may itself take a long time to run to completion + * before we can present the framebuffer. + */ + i915_gem_object_wait_priority(obj, 0, + I915_PRIORITY_DISPLAY, + I915_PREEMPTION_TIMEOUT_DISPLAY); mutex_unlock(&dev_priv->drm.struct_mutex); i915_gem_object_unpin_pages(obj);