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=-6.5 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 20C30C33CB7 for ; Mon, 27 Jan 2020 13:11:29 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 E1F4620716 for ; Mon, 27 Jan 2020 13:11:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="E1CIsw+H" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E1F4620716 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:45084 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iw4Aq-0007mW-2Z for qemu-devel@archiver.kernel.org; Mon, 27 Jan 2020 08:11:28 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:46470) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iw4AD-0007LD-R8 for qemu-devel@nongnu.org; Mon, 27 Jan 2020 08:10:51 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iw4AB-0003bY-Q2 for qemu-devel@nongnu.org; Mon, 27 Jan 2020 08:10:48 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:34321 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iw4AB-0003ai-N2 for qemu-devel@nongnu.org; Mon, 27 Jan 2020 08:10:47 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580130646; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0uxvZFay6N93u8IhS4o9XRA3k6uRFZAIjKs5xbkT94o=; b=E1CIsw+HJx0nZ7XSxqEi8bsqGIYa36q7hb3D1lZosMGfKj8aFMR+gu3rgAXAt+JsatxIxv Pwb5mqiX7a2YrwWOi3jU0Y73UNTZRqP/TxR/mpGiiLEJJcDOz3bjaIH0m3bauRusEvp0W8 vWvH0XnNGgHWDZM1w1ktWrZgGTxbsEY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-246-kcf_gN2DPVaZyZo6bHSKLg-1; Mon, 27 Jan 2020 08:10:43 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 285BF477; Mon, 27 Jan 2020 13:10:42 +0000 (UTC) Received: from gondolin (ovpn-116-220.ams2.redhat.com [10.36.116.220]) by smtp.corp.redhat.com (Postfix) with ESMTP id 447E4863CF; Mon, 27 Jan 2020 13:10:34 +0000 (UTC) Date: Mon, 27 Jan 2020 14:10:31 +0100 From: Cornelia Huck To: Stefan Hajnoczi Subject: Re: [PATCH v2 2/4] virtio-scsi: default num_queues to -smp N Message-ID: <20200127141031.6e108839.cohuck@redhat.com> In-Reply-To: <20200124100159.736209-3-stefanha@redhat.com> References: <20200124100159.736209-1-stefanha@redhat.com> <20200124100159.736209-3-stefanha@redhat.com> Organization: Red Hat GmbH MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-MC-Unique: kcf_gN2DPVaZyZo6bHSKLg-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 205.139.110.120 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Fam Zheng , Eduardo Habkost , qemu-block@nongnu.org, "Michael S. Tsirkin" , qemu-devel@nongnu.org, Max Reitz , Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, 24 Jan 2020 10:01:57 +0000 Stefan Hajnoczi wrote: > Automatically size the number of request virtqueues to match the number "If the pci transport is used, ..." ? > of vCPUs. This ensures that completion interrupts are handled on the > same vCPU that submitted the request. No IPI is necessary to complete > an I/O request and performance is improved. "For other transports, the number of request queues continues to default to 1." ? > > Signed-off-by: Stefan Hajnoczi > --- > hw/core/machine.c | 3 +++ > hw/scsi/vhost-scsi.c | 3 ++- > hw/scsi/vhost-user-scsi.c | 3 ++- > hw/scsi/virtio-scsi.c | 6 +++++- > hw/virtio/vhost-scsi-pci.c | 10 ++++++++-- > hw/virtio/vhost-user-scsi-pci.c | 10 ++++++++-- > hw/virtio/virtio-scsi-pci.c | 10 ++++++++-- > include/hw/virtio/virtio-scsi.h | 2 ++ > 8 files changed, 38 insertions(+), 9 deletions(-) > (...) > diff --git a/hw/virtio/vhost-scsi-pci.c b/hw/virtio/vhost-scsi-pci.c > index e8dfbfc60f..38a8f0c3ef 100644 > --- a/hw/virtio/vhost-scsi-pci.c > +++ b/hw/virtio/vhost-scsi-pci.c > @@ -17,6 +17,7 @@ > #include "qemu/osdep.h" > > #include "standard-headers/linux/virtio_pci.h" > +#include "hw/boards.h" > #include "hw/qdev-properties.h" > #include "hw/virtio/vhost-scsi.h" > #include "qapi/error.h" > @@ -47,10 +48,15 @@ static void vhost_scsi_pci_realize(VirtIOPCIProxy *vpci_dev, Error **errp) > { > VHostSCSIPCI *dev = VHOST_SCSI_PCI(vpci_dev); > DeviceState *vdev = DEVICE(&dev->vdev); > - VirtIOSCSICommon *vs = VIRTIO_SCSI_COMMON(vdev); > + VirtIOSCSIConf *conf = &dev->vdev.parent_obj.parent_obj.conf; > + > + /* 1:1 vq to vcpu mapping is ideal because it avoids IPIs */ > + if (conf->num_queues == VIRTIO_SCSI_AUTO_NUM_QUEUES) { > + conf->num_queues = current_machine->smp.cpus; This now maps the request vqs 1:1 to the vcpus. What about the fixed vqs? If they don't really matter, amend the comment to explain that? > + } > > if (vpci_dev->nvectors == DEV_NVECTORS_UNSPECIFIED) { > - vpci_dev->nvectors = vs->conf.num_queues + 3; > + vpci_dev->nvectors = conf->num_queues + VIRTIO_SCSI_VQ_NUM_FIXED + 1; > } > > qdev_set_parent_bus(vdev, BUS(&vpci_dev->bus));