From: Maxime Coquelin <maxime.coquelin@redhat.com>
To: Jens Freimann <jfreimann@redhat.com>, dev@dpdk.org
Cc: tiwei.bie@intel.com, Gavin.Hu@arm.com
Subject: Re: [dpdk-dev] [PATCH v12 00/10] implement packed virtqueues
Date: Thu, 13 Dec 2018 17:38:02 +0100 [thread overview]
Message-ID: <9b395ae1-712f-5d7b-5561-7bd0e55df187@redhat.com> (raw)
In-Reply-To: <20181213123453.15035-1-jfreimann@redhat.com>
On 12/13/18 1:34 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
>
>
> 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: vring init for packed queues
> net/virtio: add packed virtqueue defines
> net/virtio: add packed virtqueue helpers
> net/virtio: dump packed virtqueue data
> net/virtio: implement transmit path for packed queues
Note that the series build is broken until this patch.
> net/virtio: implement receive path for packed queues
> net/virtio: add virtio send command packed queue support
> net/virtio-user: ctrl virtqueue not supported with packed vqs
> 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 | 227 +++++--
> drivers/net/virtio/virtio_ethdev.h | 8 +
> drivers/net/virtio/virtio_pci.h | 7 +
> drivers/net/virtio/virtio_ring.h | 64 +-
> drivers/net/virtio/virtio_rxtx.c | 620 +++++++++++++++++-
> .../net/virtio/virtio_user/virtio_user_dev.c | 25 +-
> .../net/virtio/virtio_user/virtio_user_dev.h | 2 +-
> drivers/net/virtio/virtio_user_ethdev.c | 14 +-
> drivers/net/virtio/virtqueue.c | 22 +
> drivers/net/virtio/virtqueue.h | 122 +++-
> 10 files changed, 1035 insertions(+), 76 deletions(-)
>
next prev parent reply other threads:[~2018-12-13 16:38 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-13 12:34 Jens Freimann
2018-12-13 12:34 ` [dpdk-dev] [PATCH v12 01/10] net/virtio: vring init for packed queues Jens Freimann
2018-12-13 16:11 ` Maxime Coquelin
2018-12-13 12:34 ` [dpdk-dev] [PATCH v12 02/10] net/virtio: add packed virtqueue defines Jens Freimann
2018-12-13 12:34 ` [dpdk-dev] [PATCH v12 03/10] net/virtio: add packed virtqueue helpers Jens Freimann
2018-12-13 16:09 ` Maxime Coquelin
2018-12-13 22:38 ` Jens Freimann
2018-12-13 12:34 ` [dpdk-dev] [PATCH v12 04/10] net/virtio: dump packed virtqueue data Jens Freimann
2018-12-13 12:34 ` [dpdk-dev] [PATCH v12 05/10] net/virtio: implement transmit path for packed queues Jens Freimann
2018-12-13 12:34 ` [dpdk-dev] [PATCH v12 06/10] net/virtio: implement receive " Jens Freimann
2018-12-13 16:34 ` Maxime Coquelin
2018-12-13 12:34 ` [dpdk-dev] [PATCH v12 07/10] net/virtio: add virtio send command packed queue support Jens Freimann
2018-12-13 12:34 ` [dpdk-dev] [PATCH v12 08/10] net/virtio-user: add option to use packed queues Jens Freimann
2018-12-13 12:34 ` [dpdk-dev] [PATCH v12 09/10] net/virtio-user: ctrl virtqueue not supported with packed vqs Jens Freimann
2018-12-13 16:42 ` Maxime Coquelin
2018-12-13 22:35 ` Jens Freimann
2018-12-13 12:34 ` [dpdk-dev] [PATCH v12 10/10] net/virtio: enable packed virtqueues by default Jens Freimann
2018-12-13 16:38 ` Maxime Coquelin [this message]
2018-12-13 22:36 ` [dpdk-dev] [PATCH v12 00/10] implement packed virtqueues Jens Freimann
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