RE: [PATCH rdma-next 0/3] Support out of order data placement

Parav Pandit
2017-06-12T22:16:26Z

Hi Jason,

> -----Original Message-----
> From: Jason Gunthorpe [mailto:jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org]
> Sent: Monday, June 12, 2017 5:08 PM
> To: Parav Pandit <parav-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> Cc: Tom Talpey <tom-CLs1Zie5N5HQT0dZR+AlfA@public.gmane.org>; Bart Van Assche
> <Bart.VanAssche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>; leon-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org; dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org;
> linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; Idan Burstein <idanb-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> Subject: Re: [PATCH rdma-next 0/3] Support out of order data placement
>
> On Mon, Jun 12, 2017 at 09:59:22PM +0000, Parav Pandit wrote:
> > Hi Jason,
> >
> > > From: Jason Gunthorpe [mailto:jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org]
> > > Sent: Monday, June 12, 2017 4:42 PM
> > > To: Parav Pandit <parav-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> > > Cc: Tom Talpey <tom-CLs1Zie5N5HQT0dZR+AlfA@public.gmane.org>; Bart Van Assche
> > > <Bart.VanAssche-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org>; leon-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org;
> dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org;
> > > linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; Idan Burstein <idanb-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
> > > Subject: Re: [PATCH rdma-next 0/3] Support out of order data
> > > placement
> > >
> > > On Mon, Jun 12, 2017 at 09:32:30PM +0000, Parav Pandit wrote:
> > >
> > > > There can be cases in deployment where responder has support for
> > > > receiving out-of-order, but requester doesn't. Read responses
> > >
> > > You still haven't explained at all what the transmitter side does
> differently..
> >
> > Let's say
> > Read-1
> > Read-2 are issued by requester.
> >
> > For some reason read response for each read arrived via different path
> > to requester, If ooo is enabled on a QP they will be processed
> > correctly. Else read responses for 2nd read could be dropped.
>
> This is still only discussing the reciever side of a QP.
>
> > transmitter of read responder is different when ooo is enabled.
>
> And I keep asking you to explain what is different about the transmitter
> side.
Above sequence explains read_response_transmitter behavior.
I will check with hardware team if there is anything done differently at write_transmitter (requester) other than what I explained above.

>
> Jason