Re: [PATCH 0/7] IB/hfi1: Remove write() and use ioctl() for user access

[Leon Romanovsky]

On Thu, Apr 14, 2016 at 01:48:31PM -0400, Ira Weiny wrote:
> On Thu, Apr 14, 2016 at 10:45:50AM -0600, Jason Gunthorpe wrote:
> > On Thu, Apr 14, 2016 at 08:41:35AM -0700, Dennis Dalessandro wrote:
> > > This patch series removes the write() interface for user access in favor of an
> > > ioctl() based approach. This is in response to the complaint that we had
> > > different handlers for write() and writev() doing different things and expecting
> > > different types of data. See:
> > 
> > I think we should wait on applying these patches until we globally sort out
> > what to do with the rdma uapi.
> > 
> > It just doesn't make alot of sense for drivers to have their own personal
> > char devices. :(
> 
> I'm afraid I have to disagree at this time.  Someday we may have "1 char device
> to rule them all" but right now we don't have any line of sight to that
> solution.  It may be _years_ before we can agree to the semantics which will
> work for all high speed, kernel bypass, rdma, low latency, network devices.

You didn't ever try to come and work on the solution. We talked about
finite time frame (_months_) which is doable based on knowledge that user
space parts are developed by the same companies and all our future changes
will be in one subsystem.

You were supposed to prepare "wish list" from this new API as an initial
phase. If you do it, you will find that it is very short and in the
initial meeting you will see that it similar to other participants in
linux-rdma community.

> 
> We need to fix the write/writev problem now.[1]

No, this driver in staging and the proper way to move it out will be to
converge on common API and one clear path instead of duplicating the
interfaces and "inventing the wheel".

> 
> Ira
> 
> [1] https://www.spinics.net/lists/linux-rdma/msg34451.html
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Attachment: signature.asc
Description: Digital signature