From patchwork Fri Mar 30 10:39:00 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10317579 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 91A41602D6 for ; Fri, 30 Mar 2018 10:39:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8181E286DF for ; Fri, 30 Mar 2018 10:39:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 75B39286C8; Fri, 30 Mar 2018 10:39:40 +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 E6B7E286C8 for ; Fri, 30 Mar 2018 10:39:39 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F25066E026; Fri, 30 Mar 2018 10:39:38 +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 2C40E6E026 for ; Fri, 30 Mar 2018 10:39:34 +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 11213804-1500050 for multiple; Fri, 30 Mar 2018 11:39:23 +0100 Received: by haswell.alporthouse.com (sSMTP sendmail emulation); Fri, 30 Mar 2018 11:39:22 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Fri, 30 Mar 2018 11:39:00 +0100 Message-Id: <20180330103915.23018-3-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.16.3 In-Reply-To: <20180330103915.23018-1-chris@chris-wilson.co.uk> References: <20180330103915.23018-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 X-Originating-IP: 78.156.65.138 X-Country: code=GB country="United Kingdom" ip=78.156.65.138 Subject: [Intel-gfx] [PATCH 02/17] drm/i915/execlists: Set queue priority from secondary port 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: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP We can refine our current execlists->queue_priority if we inspect ELSP[1] rather than the head of the unsubmitted queue. Currently, we use the unsubmitted queue and say that if a subsequent request is more than important than the current queue, we will rerun the submission tasklet to evaluate the need for preemption. However, we only want to preempt if we need to jump ahead of a currently executing request in ELSP. The second reason for running the submission tasklet is amalgamate requests into the active context on ELSP[0] to avoid a stall when ELSP[0] drains. (Though repeatedly amalgamating requests into the active context and triggering many lite-restore is off question gain, the goal really is to put a context into ELSP[1] to cover the interrupt.) So if instead of looking at the head of the queue, we look at the context in ELSP[1] we can answer both of the questions more accurately -- we don't need to rerun the submission tasklet unless our new request is important enough to feed into, at least, ELSP[1]. References: f6322eddaff7 ("drm/i915/preemption: Allow preemption between submission ports") Signed-off-by: Chris Wilson Cc: Michał Winiarski Cc: Michel Thierry Cc: Mika Kuoppala Cc: Tvrtko Ursulin --- drivers/gpu/drm/i915/intel_lrc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 2d2d33becce3..a3fd9683f9d1 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -712,7 +712,8 @@ static void execlists_dequeue(struct intel_engine_cs *engine) kmem_cache_free(engine->i915->priorities, p); } done: - execlists->queue_priority = rb ? to_priolist(rb)->priority : INT_MIN; + execlists->queue_priority = + port != execlists->port ? rq_prio(last) : INT_MIN; execlists->first = rb; if (submit) port_assign(port, last);