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,URIBL_BLOCKED,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 993A9C43457 for ; Thu, 15 Oct 2020 11:27:03 +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 407022080A for ; Thu, 15 Oct 2020 11:27:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 407022080A 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 C39DA6EC8F; Thu, 15 Oct 2020 11:26:49 +0000 (UTC) Received: from mblankhorst.nl (mblankhorst.nl [141.105.120.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id A11ED6EC6F for ; Thu, 15 Oct 2020 11:26:40 +0000 (UTC) From: Maarten Lankhorst To: intel-gfx@lists.freedesktop.org Date: Thu, 15 Oct 2020 13:26:25 +0200 Message-Id: <20201015112627.1142745-62-maarten.lankhorst@linux.intel.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201015112627.1142745-1-maarten.lankhorst@linux.intel.com> References: <20201015112627.1142745-1-maarten.lankhorst@linux.intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH v3 61/63] drm/i915: Keep userpointer bindings if seqcount is unchanged, v2. 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: Dan Carpenter 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. Changes since v1: - Missing mutex_unlock, reported by kbuild. Reported-by: kernel test robot Reported-by: Dan Carpenter Signed-off-by: Maarten Lankhorst --- drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 27 ++++++++++++++++++--- 1 file changed, 24 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 fccf131d2b62..b0c1cc5fa917 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c @@ -263,12 +263,33 @@ 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)) { + spin_lock(&i915->mm.notifier_lock); + if (obj->userptr.pvec && + !mmu_interval_read_retry(&obj->userptr.notifier, + obj->userptr.notifier_seq)) { + obj->userptr.page_ref++; + + /* We can keep using the current binding, this is the fastpath */ + ret = 1; + } + spin_unlock(&i915->mm.notifier_lock); + } + + 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