From patchwork Thu Apr 2 08:08:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11470269 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 7E7A1159A for ; Thu, 2 Apr 2020 08:08:17 +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 6663A2078B for ; Thu, 2 Apr 2020 08:08:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6663A2078B 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 7C0176EA01; Thu, 2 Apr 2020 08:08:14 +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 7BF116EA01 for ; Thu, 2 Apr 2020 08:08:13 +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 20772773-1500050 for multiple; Thu, 02 Apr 2020 09:08:05 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Thu, 2 Apr 2020 09:08:05 +0100 Message-Id: <20200402080805.20292-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH] drm/i915/gt: Add one more rcu_barrier() after draining the ppGTT freelist 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 gen7 full-ppgtt uses nested vm references (the ppGTT is a slot within the global GTT and so has a buried i915_ggtt) we may need to go through a couple of RCU barriers before we have freed all the structs. Signed-off-by: Chris Wilson --- drivers/gpu/drm/i915/gt/intel_ggtt.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c index 894d08e5a21f..cb31ed712db3 100644 --- a/drivers/gpu/drm/i915/gt/intel_ggtt.c +++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c @@ -684,8 +684,9 @@ static void ggtt_cleanup_hw(struct i915_ggtt *ggtt) atomic_set(&ggtt->vm.open, 0); - rcu_barrier(); /* flush the RCU'ed__i915_vm_release */ - flush_workqueue(ggtt->vm.i915->wq); + do { /* flush the RCU'ed__i915_vm_release */ + rcu_barrier(); + } while (flush_workqueue(ggtt->vm.i915->wq)); mutex_lock(&ggtt->vm.mutex);