From patchwork Thu Mar 5 05:48:48 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 446619 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id E687214015A for ; Thu, 5 Mar 2015 16:53:50 +1100 (AEDT) Received: from localhost ([::1]:48471 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YTOjF-0005IC-5a for incoming@patchwork.ozlabs.org; Thu, 05 Mar 2015 00:53:49 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38275) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YTOfO-0006Rg-An for qemu-devel@nongnu.org; Thu, 05 Mar 2015 00:49:51 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YTOfN-00023h-4f for qemu-devel@nongnu.org; Thu, 05 Mar 2015 00:49:50 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33562) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YTOfM-00023d-TY for qemu-devel@nongnu.org; Thu, 05 Mar 2015 00:49:49 -0500 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t255nlbm003271 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 5 Mar 2015 00:49:47 -0500 Received: from jason-ThinkPad-T430s.nay.redhat.com ([10.66.70.106]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t255mx4G006801; Thu, 5 Mar 2015 00:49:44 -0500 From: Jason Wang To: qemu-devel@nongnu.org Date: Thu, 5 Mar 2015 13:48:48 +0800 Message-Id: <1425534531-6305-12-git-send-email-jasowang@redhat.com> In-Reply-To: <1425534531-6305-1-git-send-email-jasowang@redhat.com> References: <1425534531-6305-1-git-send-email-jasowang@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Jason Wang , Anthony Liguori , "Michael S. Tsirkin" Subject: [Qemu-devel] [PATCH V3 11/14] virtio-pci: speedup MSI-X masking and unmasking X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org This patch tries to speed up the MSI-X masking and unmasking through the mapping between vector and queues. With this patch it will there's no need to go through all possible virtqueues, which may help to reduce the time spent when doing MSI-X masking/unmasking a single vector when more than hundreds or even thousands of virtqueues were supported. Tested with 80 queue pairs virito-net-pci by changing the smp affinity in the background and doing netperf in the same time: Before the patch: 5711.70 Gbits/sec After the patch: 6830.98 Gbits/sec About 19.6% improvements in throughput. Cc: Anthony Liguori Cc: Michael S. Tsirkin Signed-off-by: Jason Wang --- hw/virtio/virtio-pci.c | 40 +++++++++++++++++++++------------------- 1 file changed, 21 insertions(+), 19 deletions(-) diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index 280bba2..327a3fc 100644 --- a/hw/virtio/virtio-pci.c +++ b/hw/virtio/virtio-pci.c @@ -676,28 +676,30 @@ static int virtio_pci_vector_unmask(PCIDevice *dev, unsigned vector, { VirtIOPCIProxy *proxy = container_of(dev, VirtIOPCIProxy, pci_dev); VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); - int ret, queue_no; + VirtQueue *vq = virtio_vector_first_queue(vdev, vector); + int ret, index, unmasked = 0; - for (queue_no = 0; queue_no < proxy->nvqs_with_notifiers; queue_no++) { - if (!virtio_queue_get_num(vdev, queue_no)) { + while (vq) { + index = virtio_queue_get_index(vdev, vq); + if (!virtio_queue_get_num(vdev, index)) { break; } - if (virtio_queue_vector(vdev, queue_no) != vector) { - continue; - } - ret = virtio_pci_vq_vector_unmask(proxy, queue_no, vector, msg); + ret = virtio_pci_vq_vector_unmask(proxy, index, vector, msg); if (ret < 0) { goto undo; } + vq = virtio_vector_next_queue(vq); + ++unmasked; } + return 0; undo: - while (--queue_no >= 0) { - if (virtio_queue_vector(vdev, queue_no) != vector) { - continue; - } - virtio_pci_vq_vector_mask(proxy, queue_no, vector); + vq = virtio_vector_first_queue(vdev, vector); + while (vq && --unmasked >= 0) { + index = virtio_queue_get_index(vdev, vq); + virtio_pci_vq_vector_mask(proxy, index, vector); + vq = virtio_vector_next_queue(vq); } return ret; } @@ -706,16 +708,16 @@ static void virtio_pci_vector_mask(PCIDevice *dev, unsigned vector) { VirtIOPCIProxy *proxy = container_of(dev, VirtIOPCIProxy, pci_dev); VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus); - int queue_no; + VirtQueue *vq = virtio_vector_first_queue(vdev, vector); + int index; - for (queue_no = 0; queue_no < proxy->nvqs_with_notifiers; queue_no++) { - if (!virtio_queue_get_num(vdev, queue_no)) { + while (vq) { + index = virtio_queue_get_index(vdev, vq); + if (!virtio_queue_get_num(vdev, index)) { break; } - if (virtio_queue_vector(vdev, queue_no) != vector) { - continue; - } - virtio_pci_vq_vector_mask(proxy, queue_no, vector); + virtio_pci_vq_vector_mask(proxy, index, vector); + vq = virtio_vector_next_queue(vq); } }