From patchwork Wed Nov 27 11:58:13 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11263891 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 6C39715AB for ; Wed, 27 Nov 2019 11:58:21 +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 547ED2071E for ; Wed, 27 Nov 2019 11:58:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 547ED2071E 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 D735D6E0F6; Wed, 27 Nov 2019 11:58:20 +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 C36086E0F6 for ; Wed, 27 Nov 2019 11:58:19 +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 19357522-1500050 for multiple; Wed, 27 Nov 2019 11:58:19 +0000 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Wed, 27 Nov 2019 11:58:13 +0000 Message-Id: <20191127115813.3345823-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.24.0 MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH] drm/i915/gt: Defer breadcrumb processing to after the irq handler 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" The design of our interrupt handlers is that we ack the receipt of the interrupt first, inside the critical section where the master interrupt control is off and other cpus cannot start processing the next interrupt; and then process the interrupt events afterwards. However, Icelake introduced a whole new set of banked GT_IIR that are inherently serialised and slow to retrieve the IIR and must be processed within the critical section. We can still push our breadcrumbs out of this critical section by using our irq_worker. On bdw+, this should not make too much of a difference as we only slightly defer the breadcrumbs, but on icl+ this should make a big difference to our throughput of interrupts from concurrently executing engines. Signed-off-by: Chris Wilson Reviewed-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/gt/intel_gt_irq.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/gt/intel_gt_irq.c b/drivers/gpu/drm/i915/gt/intel_gt_irq.c index 973ee7eded64..332b12a574fb 100644 --- a/drivers/gpu/drm/i915/gt/intel_gt_irq.c +++ b/drivers/gpu/drm/i915/gt/intel_gt_irq.c @@ -28,7 +28,7 @@ cs_irq_handler(struct intel_engine_cs *engine, u32 iir) tasklet = true; if (iir & GT_RENDER_USER_INTERRUPT) { - intel_engine_breadcrumbs_irq(engine); + intel_engine_queue_breadcrumbs(engine); tasklet |= intel_engine_needs_breadcrumb_tasklet(engine); }