From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 02DFFC433E0 for ; Wed, 24 Jun 2020 08:03:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D2FE1212CC for ; Wed, 24 Jun 2020 08:03:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390264AbgFXID1 (ORCPT ); Wed, 24 Jun 2020 04:03:27 -0400 Received: from mail.fireflyinternet.com ([109.228.58.192]:62453 "EHLO fireflyinternet.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2387606AbgFXID1 (ORCPT ); Wed, 24 Jun 2020 04:03:27 -0400 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 21599206-1500050 for multiple; Wed, 24 Jun 2020 09:03:20 +0100 From: Chris Wilson To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, Chris Wilson Subject: [PATCH 2/2] drm/i915/gem: Use mmu_notifier_range_mayfail() to avoid waiting inside reclaim Date: Wed, 24 Jun 2020 09:02:48 +0100 Message-Id: <20200624080248.3701-2-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200624080248.3701-1-chris@chris-wilson.co.uk> References: <20200624080248.3701-1-chris@chris-wilson.co.uk> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The direct reclaim path may trigger the mmu_notifier callback as part of try_to_unmap_one. As this is purely an opportunitistic attempt to reclaim pages, and will be called from any allocation context under unknown conditions (that include attempting to allocate pages for the userptr object itself and subsequently trying to reclaim parts of the partially acquired object) we have to be careful never to wait on anything being held by the calling context. Since that is unknown, we have to avoid waiting from inside direct reclaim. Signed-off-by: Chris Wilson --- drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c index 9c53eb883400..72cfb91230ea 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -103,6 +103,7 @@ userptr_mn_invalidate_range_start(struct mmu_notifier *_mn, it = interval_tree_iter_first(&mn->objects, range->start, end); while (it) { struct drm_i915_gem_object *obj; + unsigned int flags; if (!mmu_notifier_range_blockable(range)) { ret = -EAGAIN; @@ -126,9 +127,12 @@ userptr_mn_invalidate_range_start(struct mmu_notifier *_mn, } spin_unlock(&mn->lock); - ret = i915_gem_object_unbind(obj, - I915_GEM_OBJECT_UNBIND_ACTIVE | - I915_GEM_OBJECT_UNBIND_BARRIER); + flags = (I915_GEM_OBJECT_UNBIND_ACTIVE | + I915_GEM_OBJECT_UNBIND_BARRIER); + if (mmu_notifier_range_mayfail(range)) + flags = 0; + + ret = i915_gem_object_unbind(obj, flags); if (ret == 0) ret = __i915_gem_object_put_pages(obj); i915_gem_object_put(obj); -- 2.20.1