From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id 912A21BB2C for ; Tue, 18 Dec 2018 15:02:21 +0100 (CET) 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 mx1.redhat.com (Postfix) with ESMTPS id B65FB4628B; Tue, 18 Dec 2018 14:02:20 +0000 (UTC) Received: from [10.36.112.55] (ovpn-112-55.ams2.redhat.com [10.36.112.55]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4258B6013D; Tue, 18 Dec 2018 14:02:11 +0000 (UTC) To: Jens Freimann , dev@dpdk.org Cc: tiwei.bie@intel.com, Gavin.Hu@arm.com References: <20181217213139.19299-1-jfreimann@redhat.com> From: Maxime Coquelin Message-ID: Date: Tue, 18 Dec 2018 15:02:08 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.1 MIME-Version: 1.0 In-Reply-To: <20181217213139.19299-1-jfreimann@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Tue, 18 Dec 2018 14:02:20 +0000 (UTC) Subject: Re: [dpdk-dev] [PATCH v14 00/10] implement packed virtqueues X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 18 Dec 2018 14:02:22 -0000 On 12/17/18 10:31 PM, Jens Freimann wrote: > This is a basic implementation of packed virtqueues as specified in the > Virtio 1.1 draft. A compiled version of the current draft is available > at https://github.com/oasis-tcs/virtio-docs.git (or as .pdf at > https://github.com/oasis-tcs/virtio-docs/blob/master/virtio-v1.1-packed-wd10.pdf > > A packed virtqueue is different from a split virtqueue in that it > consists of only a single descriptor ring that replaces available and > used ring, index and descriptor pointers. > > Each descriptor is readable and writable and has a flags field. These flags > will mark if a descriptor is available or used. To detect new available descriptors > even after the ring has wrapped, device and driver each have a > single-bit wrap counter that is flipped from 0 to 1 and vice versa every time > the last descriptor in the ring is used/made available. > > With this patch set I see performance equal or slightly better (+2-3%) in a PVP > scenario compared to split virtqueues (v18.11 in host) > > regards, > Jens > > v13->v14: > * replace (_)set_desc_avail() > * remove unrelated changes in split vq code > * remove trailing line > * remove RING_EVENT_IDX code from virtqueue_enable_intr_packed() > * set interrupt disable flag unconditionally > * change error message for disabled control virtqueues > > v12->v13: > * re-order patches 1-3 to address Maximes comment. Move all defines and > data structures to patch one, all helpers to patch 2. > * build-tested and ran checkpatch on all patches again > * add split/packed versions for virtio_enable_intr() > * remove redundant changes from split vq code > * just return -1 when cq is enabled for packed vqs in virtio-user > > v11->v12: > * add a patch to disable control vq when packed vq is enabled. > I have a patch to support this but it needs a bit more work > and I think it shouldn't stop this series from being applied > * rework mergeable receive buffer code to be more efficient, by > batching descriptor refill, similar to what Maxime proposed for > split virtqueues > * removed unnecessary checks in virtio_recv_mergeable_pkts_packed > (Maxime) > * Did not merge receive functions as Maxime suggested because it seemed > to cause a small performance regression > * Move event_flags_shadow from patch 3 to 1 (Maxime) > * Did not merge xmit functions and call _split/_packed functions from > there because it seemed to cause small performance drop (-0.5%) > (Maxime) > > v10-v11: > * this version includes some fixes from Tiwei, so I added his > Signed-off-by to some of the patches > * fix hang with mergable rx buffers (Tiwei) > * clean-up code and simplify buffer handling (Tiwei) > * rebase to current virtio-next master branch > > v9-v10: > * don't mix index into buffer list and descriptors > * whitespace and formatting issues > * remove "VQ:" in dump virtqueue patch > * add extra packed vring struct to virtqueue and change function > prototypes and code accordingly > * move wrap_counters to virtqueue > * make if-conditions for packed and !packed more clear in > set_rxtx_funcs() > * initialize wrap counters in first patch, instead of rx and tx > implementation patch > * make virtio-user not supported with packed virtqueues, to > be fixed in other patch set? > > v8-v9: > * fix virtio_ring_free_chain_packed() to handle descriptors > correctly in case of out-of-order > * fix check in virtqueue_xmit_cleanup_packed() to improve performance > > v7->v8: > * move desc_is_used change to correct patch > * remove trailing newline > * correct xmit code, flags update and memory barrier > * move packed desc init to dedicated function, split > and packed variant > > > > Jens Freimann (9): > net/virtio: add packed virtqueue defines > net/virtio: add packed virtqueue helpers > net/virtio: vring init for packed queues > net/virtio: dump packed virtqueue data > net/virtio: implement transmit path for packed queues > net/virtio: implement receive path for packed queues > net/virtio: add virtio send command packed queue support > net/virtio-user: fail if cq used with packed vq > net/virtio: enable packed virtqueues by default > > Yuanhan Liu (1): > net/virtio-user: add option to use packed queues > > drivers/net/virtio/virtio_ethdev.c | 228 +++++-- > drivers/net/virtio/virtio_ethdev.h | 8 + > drivers/net/virtio/virtio_pci.h | 7 + > drivers/net/virtio/virtio_ring.h | 58 +- > drivers/net/virtio/virtio_rxtx.c | 611 +++++++++++++++++- > .../net/virtio/virtio_user/virtio_user_dev.c | 27 +- > .../net/virtio/virtio_user/virtio_user_dev.h | 2 +- > drivers/net/virtio/virtio_user_ethdev.c | 14 +- > drivers/net/virtio/virtqueue.c | 43 +- > drivers/net/virtio/virtqueue.h | 109 +++- > 10 files changed, 1044 insertions(+), 63 deletions(-) > Applied to dpdk-next-virtio Thanks, Maxime