From: Dennis Dalessandro <dennis.dalessandro@intel.com>
To: Jason Gunthorpe <jgg@ziepe.ca>
Cc: dledford@redhat.com, linux-rdma@vger.kernel.org
Subject: Re: [PATCH for-next 00/16] New hfi1 feature: Accelerated IP
Date: Tue, 11 Feb 2020 16:58:00 -0500 [thread overview]
Message-ID: <cf3d8011-a9c5-9e63-131b-42a5dd45e4f8@intel.com> (raw)
In-Reply-To: <20200210183249.GA4182@ziepe.ca>
On 2/10/2020 1:32 PM, Jason Gunthorpe wrote:
> On Mon, Feb 10, 2020 at 12:36:02PM -0500, Dennis Dalessandro wrote:
>> On 2/10/2020 8:31 AM, Jason Gunthorpe wrote:
>>> On Mon, Feb 10, 2020 at 08:18:05AM -0500, Dennis Dalessandro wrote:
>>>> This patch series is an accelerated ipoib using the rdma netdev mechanism
>>>> already present in ipoib. A new device capability bit,
>>>> IB_DEVICE_RDMA_NETDEV_OPA, triggers ipoib to create a datagram QP using the
>>>> IB_QP_CREATE_NETDEV_USE.
>>>>
>>>> The highlights include:
>>>> - Sharing send and receive resources with VNIC
>>>> - Allows for switching between connected mode and datagram mode
>>>
>>> There is still value in connected mode?
>>
>> It's really a compatibility thing. If someone wants to change modes that
>> will work. There won't be any benefit to connected mode though. The goal is
>> just to not break.
>
> I am a bit confused by this.. I thought the mlx5 implementation
> already could select connected mode?
>
> Why were core ipoib changes needed?
I don't think so, patch 15/16 seemed to be necessary to get connected
mode to work with the rdma netdev.
>
>>>> The patches are fully bisectable and stepwise implement the capability.
>>>
>>> This is alot of code to send without a performance
>>> justification.. What is it? Is it worth while?
>>
>> It avoids the scalability problem of connected mode, the number of QPs.
>> Incoming packets are spread into multiple receive contexts increasing
>> parallelism. The MTU is increased to allows 10K. It also reduces/removes the
>> verbs TX overhead by allowing packets to be sent through the SDMA engines
>> directly.
>
> No numbers to share?
No numbers directly but I can say that AIP enables line-rate performance
between two nodes with Datagram Mode, it also provides IPoFabric latency
improvements relative to standard Datagram Mode without AIP.
-Denny
prev parent reply other threads:[~2020-02-11 21:58 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-10 13:18 [PATCH for-next 00/16] New hfi1 feature: Accelerated IP Dennis Dalessandro
2020-02-10 13:18 ` [PATCH for-next 01/16] IB/hfi1: Add accelerated IP capability bit Dennis Dalessandro
2020-02-10 13:18 ` [PATCH for-next 02/16] IB/hfi1: Add functions to transmit datagram ipoib packets Dennis Dalessandro
2020-02-10 13:18 ` [PATCH for-next 03/16] IB/hfi1: Add the transmit side of a datagram ipoib RDMA netdev Dennis Dalessandro
2020-02-10 13:18 ` [PATCH for-next 04/16] IB/hfi1: Remove module parameter for KDETH qpns Dennis Dalessandro
2020-02-10 13:18 ` [PATCH for-next 05/16] IB/{rdmavt, hfi1}: Implement creation of accelerated UD QPs Dennis Dalessandro
2020-02-10 13:18 ` [PATCH for-next 06/16] IB/hfi1: RSM rules for AIP Dennis Dalessandro
2020-02-10 13:18 ` [PATCH for-next 07/16] IB/ipoib: Increase ipoib Datagram mode MTU's upper limit Dennis Dalessandro
2020-02-19 11:01 ` Erez Shitrit
2020-02-21 19:40 ` Dennis Dalessandro
2020-02-10 13:18 ` [PATCH for-next 08/16] IB/hfi1: Rename num_vnic_contexts as num_netdev_contexts Dennis Dalessandro
2020-02-10 13:19 ` [PATCH for-next 09/16] IB/hfi1: Add functions to receive accelerated ipoib packets Dennis Dalessandro
2020-02-10 13:19 ` [PATCH for-next 10/16] IB/hfi1: Add interrupt handler functions for accelerated ipoib Dennis Dalessandro
2020-02-10 13:19 ` [PATCH for-next 11/16] IB/hfi1: Add rx functions for dummy netdev Dennis Dalessandro
2020-02-10 13:19 ` [PATCH for-next 12/16] IB/hfi1: Activate the " Dennis Dalessandro
2020-02-10 13:19 ` [PATCH for-next 13/16] IB/{hfi1, ipoib, rdma}: Broadcast ping sent packets which exceeded mtu size Dennis Dalessandro
2020-02-19 0:42 ` Jason Gunthorpe
2020-02-21 19:40 ` Dennis Dalessandro
2020-02-21 23:32 ` Jason Gunthorpe
2020-03-20 13:53 ` Dennis Dalessandro
2020-02-19 13:41 ` Erez Shitrit
2020-02-21 19:40 ` Dennis Dalessandro
2020-02-10 13:19 ` [PATCH for-next 14/16] IB/hfi1: Add packet histogram trace event Dennis Dalessandro
2020-02-10 13:19 ` [PATCH for-next 15/16] IB/ipoib: Add capability to switch between datagram and connected mode Dennis Dalessandro
2020-02-10 13:20 ` [PATCH for-next 16/16] IB/hfi1: Enable the transmit side of the datagram ipoib netdev Dennis Dalessandro
2020-02-10 13:31 ` [PATCH for-next 00/16] New hfi1 feature: Accelerated IP Jason Gunthorpe
2020-02-10 17:36 ` Dennis Dalessandro
2020-02-10 18:32 ` Jason Gunthorpe
2020-02-11 21:58 ` Dennis Dalessandro [this message]
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