From: Jens Freimann <jfreimann@redhat.com>
To: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: dev@dpdk.org, tiwei.bie@intel.com, Gavin.Hu@arm.com
Subject: Re: [dpdk-dev] [PATCH v12 00/10] implement packed virtqueues
Date: Thu, 13 Dec 2018 23:36:42 +0100 [thread overview]
Message-ID: <20181213223642.yrug3hxkopse4ymf@jenstp.localdomain> (raw)
In-Reply-To: <9b395ae1-712f-5d7b-5561-7bd0e55df187@redhat.com>
On Thu, Dec 13, 2018 at 05:38:02PM +0100, Maxime Coquelin wrote:
>
>
>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.
I usually run 'git rebase -x "make"' to avoid. Must have missed it
this time, but will fix it.
regards,
Jens
prev parent reply other threads:[~2018-12-13 22:36 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 ` [dpdk-dev] [PATCH v12 00/10] implement packed virtqueues Maxime Coquelin
2018-12-13 22:36 ` Jens Freimann [this message]
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