From patchwork Wed Aug 5 12:21:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11701801 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 7BD831392 for ; Wed, 5 Aug 2020 12:22:56 +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 65D5B22D03 for ; Wed, 5 Aug 2020 12:22:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 65D5B22D03 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 E9BDC6E56D; Wed, 5 Aug 2020 12:22:49 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (unknown [77.68.26.236]) by gabe.freedesktop.org (Postfix) with ESMTPS id E89BF6E566 for ; Wed, 5 Aug 2020 12:22:47 +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 22039462-1500050 for multiple; Wed, 05 Aug 2020 13:22:31 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Wed, 5 Aug 2020 13:21:57 +0100 Message-Id: <20200805122231.23313-4-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200805122231.23313-1-chris@chris-wilson.co.uk> References: <20200805122231.23313-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 03/37] drm/i915/gt: Free stale request on destroying the virtual engine 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: , Cc: Chris Wilson Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Since preempt-to-busy, we may unsubmit a request while it is still on the HW and completes asynchronously. That means it may be retired and in the process destroy the virtual engine (as the user has closed their context), but that engine may still be holding onto the unsubmitted compelted request. Therefore we need to potentially cleanup the old request on destroying the virtual engine. We also have to keep the virtual_engine alive until after the sibling's execlists_dequeue() have finished peeking into the virtual engines, for which we serialise with RCU. Signed-off-by: Chris Wilson Cc: Tvrtko Ursulin Reviewed-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/gt/intel_lrc.c | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index 417f6b0c6c61..cb04bc5474be 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -180,6 +180,7 @@ #define EXECLISTS_REQUEST_SIZE 64 /* bytes */ struct virtual_engine { + struct rcu_head rcu; struct intel_engine_cs base; struct intel_context context; @@ -5393,10 +5394,25 @@ static void virtual_context_destroy(struct kref *kref) container_of(kref, typeof(*ve), context.ref); unsigned int n; - GEM_BUG_ON(!list_empty(virtual_queue(ve))); - GEM_BUG_ON(ve->request); GEM_BUG_ON(ve->context.inflight); + if (unlikely(ve->request)) { + struct i915_request *old; + unsigned long flags; + + spin_lock_irqsave(&ve->base.active.lock, flags); + + old = fetch_and_zero(&ve->request); + if (old) { + GEM_BUG_ON(!i915_request_completed(old)); + __i915_request_submit(old); + i915_request_put(old); + } + + spin_unlock_irqrestore(&ve->base.active.lock, flags); + } + GEM_BUG_ON(!list_empty(virtual_queue(ve))); + for (n = 0; n < ve->num_siblings; n++) { struct intel_engine_cs *sibling = ve->siblings[n]; struct rb_node *node = &ve->nodes[sibling->id].rb; @@ -5422,7 +5438,7 @@ static void virtual_context_destroy(struct kref *kref) intel_engine_free_request_pool(&ve->base); kfree(ve->bonds); - kfree(ve); + kfree_rcu(ve, rcu); } static void virtual_engine_initial_hint(struct virtual_engine *ve)