RE: [EXTERNAL] Re: [PATCH rdma-next 1/1] RDMA/mana_ib: take CQ type from the device type
From: Konstantin Taranov
Date: Tue Jan 13 2026 - 09:40:50 EST
> On Tue, Jan 13, 2026 at 12:27:57PM +0000, Konstantin Taranov wrote:
> > > >
> > > > - is_rnic_cq = !!(ucmd.flags & MANA_IB_CREATE_RNIC_CQ);
> > >
> > > You need to add code which prohibits future use of this BIT(0) in
> > > ucmd.flags for backward compatibility and maybe delete
> > > MANA_IB_CREATE_RNIC_CQ from UAPI too.
> > >
> > > Thanks
> > >
> >
> > Hi Leon. I thought that my proposed change is backward and forward
> compatible.
> > If I add code that prohibits this flag, then the older rdma-core will
> > fail to create CQ, as it sets this flag. Add rdma-core should set the flag to
> support older kernels.
> >
> > So, the current solution is as follows:
> > rdma-core always sends the flag. The kernels without this patch still use
> this flag.
> > Newer kernels just ignore the flag and create the CQ according to the client.
> > It is not fully possible to retire this flag now, as we want to be
> > backwards compatible and support older kernels and older rdma-core.
> > Or did you mean something else? Or do I miss something?
>
> There needs to be a way to document in the code that this bit is reserved
> and must not be used.
Got it! I will add comments to the code that the bit is reserved and should
not be reused.
Thanks
>
> Thanks
>
> >
> > Thanks