From patchwork Wed Aug 21 04:20:44 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 11105437 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 D17D814DB for ; Wed, 21 Aug 2019 04:21:14 +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 8582D22DD3 for ; Wed, 21 Aug 2019 04:21:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8582D22DD3 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 CDBD56E8F6; Wed, 21 Aug 2019 04:21:13 +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 2A3086E8F6 for ; Wed, 21 Aug 2019 04:21:12 +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 18208893-1500050 for multiple; Wed, 21 Aug 2019 05:20:45 +0100 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Wed, 21 Aug 2019 05:20:44 +0100 Message-Id: <20190821042044.7354-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.23.0.rc1 MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH] drm/i915/gtt: Relax assertion for pt_used 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" When inserting the final level PTE, we check that we are not overflowing the page table (checking that pt_used does not exceed the size of the table). However, we have to allow for every other PTE to be pinned by a simultaneous removal thread (as on remove we bump the pt_used counter before adjusting the table). Signed-off-by: Chris Wilson Cc: Mika Kuoppala Reviewed-by: Mika Kuoppala --- drivers/gpu/drm/i915/i915_gem_gtt.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index 081c8b79c047..94712d3eb882 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -1112,7 +1112,8 @@ static int __gen8_ppgtt_alloc(struct i915_address_space * const vm, atomic_read(&pt->used)); atomic_add(count, &pt->used); - GEM_BUG_ON(atomic_read(&pt->used) > I915_PDES); + /* All other pdes may be simultaneously removed */ + GEM_BUG_ON(atomic_read(&pt->used) > 2 * I915_PDES); *start += count; } } while (idx++, --len);