From: Jason Gunthorpe <jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
To: Erez Shitrit <erezsh-LDSdmyG8hGV8YrgS2mwiifqBs+8SCbDb@public.gmane.org>
Cc: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>,
Erez Shitrit <erezsh-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>,
Doug Ledford <dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
"linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
valex-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org
Subject: Re: [RFC v2 for accelerated IPoIB 00/6] Enhanced mode for IPoIB driver
Date: Sun, 26 Mar 2017 14:42:37 -0600 [thread overview]
Message-ID: <20170326204237.GB3113@obsidianresearch.com> (raw)
In-Reply-To: <CAAk-MO_7LVUQS_8+h9shFEXkjT6NHkzXeYRH+_8Wcjr0P+dHAw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
On Sun, Mar 26, 2017 at 07:17:13PM +0300, Erez Shitrit wrote:
> > be computed once instead of computed for every split packet. The
> > downside here is that it may be very complicated to store a kref in a
> > skb pseudo header and properly unref it at all the right times..
>
> It is an optimization, and still we need to get the ah even at the
> middle of GSO, for each skb, or to keep it somewhere, also will need
> to keep more space in the skb, more processing.
GSO is done in a way where the pseudo header is retained but not
recomputed for every fragment, much like for ethernet.
Does mlx5 even need a 'AH'? Maybe allowing the driver to provide some
bytes in the pseudo header that match the HW SQE is an overall more
efficient direction.
> > The other is to factor out the AH extraction from ipoib_start_xmit
> > into a helper function and have all the rn drivers call it to get the
> > AH.
>
> We will pay with performance degradation for each send.
Eh? Having ndo->ipoib->driver or ndo->driver->ipoib as a call chain
doesn't really matter one bit.
Jason
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next prev parent reply other threads:[~2017-03-26 20:42 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-20 19:08 [RFC v2 for accelerated IPoIB 00/6] Enhanced mode for IPoIB driver Erez Shitrit
[not found] ` <1490036908-12528-1-git-send-email-erezsh-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
2017-03-20 19:08 ` [RFC v2 for accelerated IPoIB 01/6] IB/ipoib: Separate control and data related initializations Erez Shitrit
2017-03-20 19:08 ` [RFC v2 for accelerated IPoIB 02/6] IB/ipoib: separate control from HW operation on ipoib_open/stop ndo Erez Shitrit
2017-03-20 19:08 ` [RFC v2 for accelerated IPoIB 03/6] IB/ipoib: Rename qpn to dqpn in ipoib_send and post_send functions Erez Shitrit
2017-03-20 19:08 ` [RFC v2 for accelerated IPoIB 04/6] IB/verb: Add ipoib_options struct and API Erez Shitrit
2017-03-20 19:08 ` [RFC v2 for accelerated IPoIB 05/6] IB/ipoib: Support ipoib acceleration options callbacks Erez Shitrit
2017-03-20 19:08 ` [RFC v2 for accelerated IPoIB 6/6] mlx5_ib: skeleton for mlx5_ib to support ipoib_ops Erez Shitrit
2017-03-20 20:59 ` [RFC v2 for accelerated IPoIB 00/6] Enhanced mode for IPoIB driver Jason Gunthorpe
[not found] ` <20170320205927.GA17225-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
2017-03-21 11:49 ` Leon Romanovsky
[not found] ` <20170321114955.GB2079-U/DQcQFIOTAAJjI8aNfphQ@public.gmane.org>
2017-03-21 16:15 ` Jason Gunthorpe
[not found] ` <20170321161530.GB22216-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
2017-03-21 16:49 ` Leon Romanovsky
[not found] ` <20170321164952.GE2079-U/DQcQFIOTAAJjI8aNfphQ@public.gmane.org>
2017-03-22 11:18 ` Erez Shitrit
[not found] ` <CAAk-MO_KEV9MA5Dcaz8SZagMeC4hQX456Cu8To-YRBNMeNu3pg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-03-22 16:52 ` Jason Gunthorpe
[not found] ` <20170322165238.GA26589-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
2017-03-26 16:17 ` Erez Shitrit
[not found] ` <CAAk-MO_7LVUQS_8+h9shFEXkjT6NHkzXeYRH+_8Wcjr0P+dHAw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-03-26 20:42 ` Jason Gunthorpe [this message]
[not found] ` <20170326204237.GB3113-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
2017-03-28 11:40 ` Erez Shitrit
[not found] ` <CAAk-MO8Z7wKGFU5empgHGpN73cGMkKMi+ijnTHpfXBD5oZ+cGQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2017-03-29 13:46 ` Jason Gunthorpe
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