Re: [PATCH for-next] IB/cma: Introduce rdma_set_min_rnr_timer()

Jason Gunthorpe
2021-03-31T12:01:30Z

On Wed, Mar 31, 2021 at 10:38:02AM +0000, Haakon Bugge wrote:
>
>
> > On 31 Mar 2021, at 01:12, Jason Gunthorpe <jgg@nvidia.com> wrote:
> >
> > On Thu, Mar 25, 2021 at 02:05:47PM +0100, Håkon Bugge wrote:
> >> Introduce the ability for both user-space and kernel ULPs to adjust
> >> the minimum RNR Retry timer. The INIT -> RTR transition executed by
> >> RDMA CM will be used for this adjustment. This avoids an additional
> >> ib_modify_qp() call.
> >
> > Can't userspace override the ibv_modify_qp() call the librdmacm wants
> > to make to do this?
>
> Not sure I understand. The point is, that user-land which intends to
> set said timer, can do so without an additional ibv_modify_qp()
> call. May be I should have added:

IIRC in userspace the application has the option to call
ibv_modify_qp() so it can just change it before it makes the call?

> Shamelessly-inspired-by: 2c1619edef61 ("IB/cma: Define option to set ack timeout and pack tos_set")

Hmm..

Jason