On Fri, Jan 22, 2021 at 08:24:57AM +0000, Christoph Lameter wrote:
> On Thu, 21 Jan 2021, Leon Romanovsky wrote:
>
> > > spin_lock_irqsave(&port->classport_lock, flags);
> > > - if ((port->classport_info.valid) &&
> > > - (port->classport_info.data.type == RDMA_CLASS_PORT_INFO_IB))
> > > + if (!port->classport_info.valid) {
> > > + /* Need to wait until the SM data is available */
> > > + spin_unlock_irqrestore(&port->classport_lock, flags);
> > > + goto redo;
> >
> > We have all potential to loop forever here, if valid doesn't change.
> >
>
> Right. So what is the right solution here? The sendonly check function could return
> an errno instead?
>
> 0 = Sendonly join is supported
> -EAGAIN = SM information is currently invalid
> -ENOSUP = SM does not support sendonly join
I would do the same flow as in update_ib_cpi(), use retry count and loop
with delay, but without workqueue.
>
> Since all SMs out there have had support for sendonly join for years now
> we could just remove the check entirely. If there is an old grizzly SM out
> there then it would not process that join request and would return an
> error.
I have no idea if it possible, if yes, this will be the best solution.
Thanks
