From patchwork Tue Oct 21 10:46:02 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Dheeraj Jamwal X-Patchwork-Id: 5114621 Return-Path: X-Original-To: patchwork-ltsi-dev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id D6114C11AC for ; Tue, 21 Oct 2014 11:10:45 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E90BB20123 for ; Tue, 21 Oct 2014 11:10:44 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E4A7B2011E for ; Tue, 21 Oct 2014 11:10:43 +0000 (UTC) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 49CF6B8B; Tue, 21 Oct 2014 11:00:29 +0000 (UTC) X-Original-To: ltsi-dev@lists.linuxfoundation.org Delivered-To: ltsi-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 829E4B32 for ; Tue, 21 Oct 2014 11:00:28 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 1F46E201B3 for ; Tue, 21 Oct 2014 11:00:28 +0000 (UTC) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga102.fm.intel.com with ESMTP; 21 Oct 2014 04:00:27 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,761,1406617200"; d="scan'208";a="617792592" Received: from ubuntu-desktop.png.intel.com ([10.221.122.25]) by fmsmga002.fm.intel.com with ESMTP; 21 Oct 2014 04:00:27 -0700 From: Dheeraj Jamwal To: ltsi-dev@lists.linuxfoundation.org Date: Tue, 21 Oct 2014 18:46:02 +0800 Message-Id: <1413889294-31328-163-git-send-email-dheerajx.s.jamwal@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1413889294-31328-1-git-send-email-dheerajx.s.jamwal@intel.com> References: <1413889294-31328-1-git-send-email-dheerajx.s.jamwal@intel.com> MIME-Version: 1.0 X-Spam-Status: No, score=-5.6 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org Subject: [LTSI-dev] [PATCH 0162/1094] drm/i915: Prevent recursion by retiring requests when the ring is full X-BeenThere: ltsi-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: "A list to discuss patches, development, and other things related to the LTSI project" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: ltsi-dev-bounces@lists.linuxfoundation.org Errors-To: ltsi-dev-bounces@lists.linuxfoundation.org X-Virus-Scanned: ClamAV using ClamSMTP From: Chris Wilson As the VM do not track activity of objects and instead use a large hammer to forcibly idle and evict all of their associated objects when one is released, it is possible for that to cause a recursion when we need to wait for free space on a ring and call retire requests. (intel_ring_begin -> intel_ring_wait_request -> i915_gem_retire_requests_ring -> i915_gem_context_free -> i915_gem_evict_vm -> i915_gpu_idle -> intel_ring_begin etc) In order to remove the requirement for calling retire-requests from intel_ring_wait_request, we have to inline a couple of steps from retiring requests, notably we have to record the position of the request we wait for and use that to update the available ring space. Signed-off-by: Chris Wilson Reviewed-by: Ville Syrjälä Signed-off-by: Daniel Vetter (cherry picked from commit 1f70999f9052f5a1b0ce1a55aff3808f2ec9fe42) Signed-off-by: Dheeraj Jamwal --- drivers/gpu/drm/i915/intel_ringbuffer.c | 25 +++++-------------------- 1 file changed, 5 insertions(+), 20 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index e9a55dc..8c1c0bc 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -1430,28 +1430,16 @@ void intel_cleanup_ring_buffer(struct intel_ring_buffer *ring) cleanup_status_page(ring); } -static int intel_ring_wait_seqno(struct intel_ring_buffer *ring, u32 seqno) -{ - int ret; - - ret = i915_wait_seqno(ring, seqno); - if (!ret) - i915_gem_retire_requests_ring(ring); - - return ret; -} - static int intel_ring_wait_request(struct intel_ring_buffer *ring, int n) { struct drm_i915_gem_request *request; - u32 seqno = 0; + u32 seqno = 0, tail; int ret; - i915_gem_retire_requests_ring(ring); - if (ring->last_retired_head != -1) { ring->head = ring->last_retired_head; ring->last_retired_head = -1; + ring->space = ring_space(ring); if (ring->space >= n) return 0; @@ -1468,6 +1456,7 @@ static int intel_ring_wait_request(struct intel_ring_buffer *ring, int n) space += ring->size; if (space >= n) { seqno = request->seqno; + tail = request->tail; break; } @@ -1482,15 +1471,11 @@ static int intel_ring_wait_request(struct intel_ring_buffer *ring, int n) if (seqno == 0) return -ENOSPC; - ret = intel_ring_wait_seqno(ring, seqno); + ret = i915_wait_seqno(ring, seqno); if (ret) return ret; - if (WARN_ON(ring->last_retired_head == -1)) - return -ENOSPC; - - ring->head = ring->last_retired_head; - ring->last_retired_head = -1; + ring->head = tail; ring->space = ring_space(ring); if (WARN_ON(ring->space < n)) return -ENOSPC;