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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 16132ECDFB3 for ; Mon, 16 Jul 2018 08:39:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C4DB4208E9 for ; Mon, 16 Jul 2018 08:39:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C4DB4208E9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730617AbeGPJFc (ORCPT ); Mon, 16 Jul 2018 05:05:32 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:46198 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728437AbeGPJFb (ORCPT ); Mon, 16 Jul 2018 05:05:31 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C6D94402315B; Mon, 16 Jul 2018 08:39:12 +0000 (UTC) Received: from redhat.com (ovpn-120-40.rdu2.redhat.com [10.10.120.40]) by smtp.corp.redhat.com (Postfix) with SMTP id EE2E72026D65; Mon, 16 Jul 2018 08:39:11 +0000 (UTC) Date: Mon, 16 Jul 2018 11:39:11 +0300 From: "Michael S. Tsirkin" To: Jason Wang Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, wexu@redhat.com, jfreimann@redhat.com, tiwei.bie@intel.com, maxime.coquelin@redhat.com Subject: Re: [PATCH net-next V2 0/8] Packed virtqueue support for vhost Message-ID: <20180716113720-mutt-send-email-mst@kernel.org> References: <1531711691-6769-1-git-send-email-jasowang@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1531711691-6769-1-git-send-email-jasowang@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Mon, 16 Jul 2018 08:39:12 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Mon, 16 Jul 2018 08:39:12 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'mst@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 16, 2018 at 11:28:03AM +0800, Jason Wang wrote: > Hi all: > > This series implements packed virtqueues. The code were tested with > Tiwei's guest driver series at https://patchwork.ozlabs.org/cover/942297/ > > > Pktgen test for both RX and TX does not show obvious difference with > split virtqueues. The main bottleneck is the guest Linux driver, since > it can not stress vhost for a 100% CPU utilization. A full TCP > benchmark is ongoing. Will test virtio-net pmd as well when it was > ready. Well the question then is why we should bother merging this if this doesn't give a performance gain. Do you see a gain in CPU utilization maybe? If not - let's wait for that TCP benchmark result? > Notes: > - This version depends on Tiwei's series at https://patchwork.ozlabs.org/cover/942297/ > > This version were tested with: > > - Zerocopy (Out of Order) support > - vIOMMU support > - mergeable buffer on/off > - busy polling on/off > - vsock (nc-vsock) > > Changes from V1: > - drop uapi patch and use Tiwei's > - split the enablement of packed virtqueue into a separate patch > > Changes from RFC V5: > > - save unnecessary barriers during vhost_add_used_packed_n() > - more compact math for event idx > - fix failure of SET_VRING_BASE when avail_wrap_counter is true > - fix not copy avail_wrap_counter during GET_VRING_BASE > - introduce SET_VRING_USED_BASE/GET_VRING_USED_BASE for syncing last_used_idx > - rename used_wrap_counter to last_used_wrap_counter > - rebase to net-next > > Changes from RFC V4: > > - fix signalled_used index recording > - track avail index correctly > - various minor fixes > > Changes from RFC V3: > > - Fix math on event idx checking > - Sync last avail wrap counter through GET/SET_VRING_BASE > - remove desc_event prefix in the driver/device structure > > Changes from RFC V2: > > - do not use & in checking desc_event_flags > - off should be most significant bit > - remove the workaround of mergeable buffer for dpdk prototype > - id should be in the last descriptor in the chain > - keep _F_WRITE for write descriptor when adding used > - device flags updating should use ADDR_USED type > - return error on unexpected unavail descriptor in a chain > - return false in vhost_ve_avail_empty is descriptor is available > - track last seen avail_wrap_counter > - correctly examine available descriptor in get_indirect_packed() > - vhost_idx_diff should return u16 instead of bool > > Changes from RFC V1: > > - Refactor vhost used elem code to avoid open coding on used elem > - Event suppression support (compile test only). > - Indirect descriptor support (compile test only). > - Zerocopy support. > - vIOMMU support. > - SCSI/VSOCK support (compile test only). > - Fix several bugs > > Jason Wang (8): > vhost: move get_rx_bufs to vhost.c > vhost: hide used ring layout from device > vhost: do not use vring_used_elem > vhost_net: do not explicitly manipulate vhost_used_elem > vhost: vhost_put_user() can accept metadata type > vhost: packed ring support > vhost: event suppression for packed ring > vhost: enable packed virtqueues > > drivers/vhost/net.c | 143 ++----- > drivers/vhost/scsi.c | 62 +-- > drivers/vhost/vhost.c | 994 ++++++++++++++++++++++++++++++++++++++++----- > drivers/vhost/vhost.h | 55 ++- > drivers/vhost/vsock.c | 42 +- > include/uapi/linux/vhost.h | 7 + > 6 files changed, 1035 insertions(+), 268 deletions(-) > > -- > 2.7.4 From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH net-next V2 0/8] Packed virtqueue support for vhost Date: Mon, 16 Jul 2018 11:39:11 +0300 Message-ID: <20180716113720-mutt-send-email-mst@kernel.org> References: <1531711691-6769-1-git-send-email-jasowang@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, maxime.coquelin@redhat.com, wexu@redhat.com To: Jason Wang Return-path: Content-Disposition: inline In-Reply-To: <1531711691-6769-1-git-send-email-jasowang@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org List-Id: netdev.vger.kernel.org On Mon, Jul 16, 2018 at 11:28:03AM +0800, Jason Wang wrote: > Hi all: > > This series implements packed virtqueues. The code were tested with > Tiwei's guest driver series at https://patchwork.ozlabs.org/cover/942297/ > > > Pktgen test for both RX and TX does not show obvious difference with > split virtqueues. The main bottleneck is the guest Linux driver, since > it can not stress vhost for a 100% CPU utilization. A full TCP > benchmark is ongoing. Will test virtio-net pmd as well when it was > ready. Well the question then is why we should bother merging this if this doesn't give a performance gain. Do you see a gain in CPU utilization maybe? If not - let's wait for that TCP benchmark result? > Notes: > - This version depends on Tiwei's series at https://patchwork.ozlabs.org/cover/942297/ > > This version were tested with: > > - Zerocopy (Out of Order) support > - vIOMMU support > - mergeable buffer on/off > - busy polling on/off > - vsock (nc-vsock) > > Changes from V1: > - drop uapi patch and use Tiwei's > - split the enablement of packed virtqueue into a separate patch > > Changes from RFC V5: > > - save unnecessary barriers during vhost_add_used_packed_n() > - more compact math for event idx > - fix failure of SET_VRING_BASE when avail_wrap_counter is true > - fix not copy avail_wrap_counter during GET_VRING_BASE > - introduce SET_VRING_USED_BASE/GET_VRING_USED_BASE for syncing last_used_idx > - rename used_wrap_counter to last_used_wrap_counter > - rebase to net-next > > Changes from RFC V4: > > - fix signalled_used index recording > - track avail index correctly > - various minor fixes > > Changes from RFC V3: > > - Fix math on event idx checking > - Sync last avail wrap counter through GET/SET_VRING_BASE > - remove desc_event prefix in the driver/device structure > > Changes from RFC V2: > > - do not use & in checking desc_event_flags > - off should be most significant bit > - remove the workaround of mergeable buffer for dpdk prototype > - id should be in the last descriptor in the chain > - keep _F_WRITE for write descriptor when adding used > - device flags updating should use ADDR_USED type > - return error on unexpected unavail descriptor in a chain > - return false in vhost_ve_avail_empty is descriptor is available > - track last seen avail_wrap_counter > - correctly examine available descriptor in get_indirect_packed() > - vhost_idx_diff should return u16 instead of bool > > Changes from RFC V1: > > - Refactor vhost used elem code to avoid open coding on used elem > - Event suppression support (compile test only). > - Indirect descriptor support (compile test only). > - Zerocopy support. > - vIOMMU support. > - SCSI/VSOCK support (compile test only). > - Fix several bugs > > Jason Wang (8): > vhost: move get_rx_bufs to vhost.c > vhost: hide used ring layout from device > vhost: do not use vring_used_elem > vhost_net: do not explicitly manipulate vhost_used_elem > vhost: vhost_put_user() can accept metadata type > vhost: packed ring support > vhost: event suppression for packed ring > vhost: enable packed virtqueues > > drivers/vhost/net.c | 143 ++----- > drivers/vhost/scsi.c | 62 +-- > drivers/vhost/vhost.c | 994 ++++++++++++++++++++++++++++++++++++++++----- > drivers/vhost/vhost.h | 55 ++- > drivers/vhost/vsock.c | 42 +- > include/uapi/linux/vhost.h | 7 + > 6 files changed, 1035 insertions(+), 268 deletions(-) > > -- > 2.7.4