From patchwork Sun Nov 15 13:32:43 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 7619031 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 4CA31BF90C for ; Sun, 15 Nov 2015 13:34:07 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 97BAA20693 for ; Sun, 15 Nov 2015 13:34:05 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 24A6A2068E for ; Sun, 15 Nov 2015 13:34:04 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2B4F16E6DF; Sun, 15 Nov 2015 05:34:01 -0800 (PST) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [87.106.93.118]) by gabe.freedesktop.org (Postfix) with ESMTP id 34CD76E6DF; Sun, 15 Nov 2015 05:33:59 -0800 (PST) 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 48284035-1500048 for multiple; Sun, 15 Nov 2015 13:33:15 +0000 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Sun, 15 Nov 2015 13:33:12 +0000 From: Chris Wilson To: Jens Axboe , intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/2] drm/i915: Break busywaiting for requests on pending signals Date: Sun, 15 Nov 2015 13:32:43 +0000 Message-Id: <1447594364-4206-1-git-send-email-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.6.2 X-Originating-IP: 78.156.65.138 X-Country: code=GB country="United Kingdom" ip=78.156.65.138 Cc: Tvrtko Ursulin , Daniel Vetter , Eero Tamminen , dri-devel@lists.freedesktop.org, stable@kernel.vger.org, "Rantala, Valtteri" X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Spam-Status: No, score=-4.8 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The busywait in __i915_spin_request() does not respect pending signals and so may consume the entire timeslice for the task instead of returning to userspace to handle the signal. Fixes regression from commit 2def4ad99befa25775dd2f714fdd4d92faec6e34 [v4.2] Author: Chris Wilson Date: Tue Apr 7 16:20:41 2015 +0100 drm/i915: Optimistically spin for the request completion Signed-off-by: Chris Wilson Cc: Jens Axboe Cc; "Rogozhkin, Dmitry V" Cc: Daniel Vetter Cc: Tvrtko Ursulin Cc: Eero Tamminen Cc: "Rantala, Valtteri" Cc: stable@kernel.vger.org Reviewed-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/i915_gem.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 5cf4a1998273..740530c571d1 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -1146,7 +1146,7 @@ static bool missed_irq(struct drm_i915_private *dev_priv, return test_bit(ring->id, &dev_priv->gpu_error.missed_irq_rings); } -static int __i915_spin_request(struct drm_i915_gem_request *req) +static int __i915_spin_request(struct drm_i915_gem_request *req, int state) { unsigned long timeout; @@ -1158,6 +1158,9 @@ static int __i915_spin_request(struct drm_i915_gem_request *req) if (i915_gem_request_completed(req, true)) return 0; + if (signal_pending_state(state, current)) + break; + if (time_after_eq(jiffies, timeout)) break; @@ -1197,6 +1200,7 @@ int __i915_wait_request(struct drm_i915_gem_request *req, struct drm_i915_private *dev_priv = dev->dev_private; const bool irq_test_in_progress = ACCESS_ONCE(dev_priv->gpu_error.test_irq_rings) & intel_ring_flag(ring); + int state = interruptible ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE; DEFINE_WAIT(wait); unsigned long timeout_expire; s64 before, now; @@ -1221,7 +1225,7 @@ int __i915_wait_request(struct drm_i915_gem_request *req, before = ktime_get_raw_ns(); /* Optimistic spin for the next jiffie before touching IRQs */ - ret = __i915_spin_request(req); + ret = __i915_spin_request(req, state); if (ret == 0) goto out; @@ -1233,8 +1237,7 @@ int __i915_wait_request(struct drm_i915_gem_request *req, for (;;) { struct timer_list timer; - prepare_to_wait(&ring->irq_queue, &wait, - interruptible ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE); + prepare_to_wait(&ring->irq_queue, &wait, state); /* We need to check whether any gpu reset happened in between * the caller grabbing the seqno and now ... */ @@ -1252,7 +1255,7 @@ int __i915_wait_request(struct drm_i915_gem_request *req, break; } - if (interruptible && signal_pending(current)) { + if (signal_pending_state(state, current)) { ret = -ERESTARTSYS; break; }