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=-12.8 required=3.0 tests=BAYES_00, 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 32ED2C04EBE for ; Mon, 12 Oct 2020 14:47:50 +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 ECB892067C for ; Mon, 12 Oct 2020 14:47:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ECB892067C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com 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 3D4076E512; Mon, 12 Oct 2020 14:47:32 +0000 (UTC) Received: from mblankhorst.nl (mblankhorst.nl [141.105.120.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id BD18F6E4AB for ; Mon, 12 Oct 2020 14:47:19 +0000 (UTC) From: Maarten Lankhorst To: intel-gfx@lists.freedesktop.org Date: Mon, 12 Oct 2020 16:47:06 +0200 Message-Id: <20201012144706.555345-62-maarten.lankhorst@linux.intel.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201012144706.555345-1-maarten.lankhorst@linux.intel.com> References: <20201012144706.555345-1-maarten.lankhorst@linux.intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v2 61/61] drm/i915: Keep userpointer bindings if seqcount is unchanged 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Instead of force unbinding and rebinding every time, we try to check if our notifier seqcount is still correct when pages are bound. This way we only rebind userptr when we need to, and prevent stalls. Signed-off-by: Maarten Lankhorst --- drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 29 ++++++++++++++++++--- 1 file changed, 26 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 96f869823844..5191e06b3d0f 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -263,12 +263,35 @@ int i915_gem_object_userptr_submit_init(struct drm_i915_gem_object *obj) if (ret) return ret; - /* Make sure userptr is unbound for next attempt, so we don't use stale pages. */ - ret = i915_gem_object_userptr_unbind(obj, false); + /* optimistically try to preserve current pages while unlocked */ + if (i915_gem_object_has_pages(obj) && + !mmu_interval_check_retry(&obj->userptr.notifier, + obj->userptr.notifier_seq)) { + ret = mutex_lock_interruptible(&i915->mm.notifier_lock); + if (!ret) { + if (obj->userptr.pvec && + !mmu_interval_read_retry(&obj->userptr.notifier, + obj->userptr.notifier_seq)) { + obj->userptr.page_ref++; + mutex_unlock(&i915->mm.notifier_lock); + + /* We can keep using the current binding, this is the fastpath */ + ret = 1; + } + } + } + + if (!ret) { + /* Make sure userptr is unbound for next attempt, so we don't use stale pages. */ + ret = i915_gem_object_userptr_unbind(obj, false); + } i915_gem_object_unlock(obj); - if (ret) + if (ret < 0) return ret; + if (ret > 0) + return 0; + notifier_seq = mmu_interval_read_begin(&obj->userptr.notifier); pvec = kvmalloc_array(num_pages, sizeof(struct page *), GFP_KERNEL); -- 2.28.0 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx