[openib-general] Re: RFC: ipath ioctls and their replacements

[Greg KH]

On Wed, Jan 18, 2006 at 09:53:08PM -0800, Bryan O'Sullivan wrote:
> On Wed, 2006-01-18 at 21:39 -0800, Greg KH wrote:
> 
> > Ok, that's fair enough.  But if you want to do something like ptys, then
> > why not just have your own filesystem for this driver?
> 
> If you think it's appropriate to implement a new filesystem to replace a
> single ioctl that returns two integers, we can probably do that, but
> more realistically, the GETPORT ioctl can probably live a long and
> untroubled life as another netlink message.

Well it only takes about 250 lines to make a new fs these days, but a
single netlink message would probably be smaller :)

> > You are just making your own type of special interface up as you
> > go, so the complexity is also there (this complexity would normally be
> > in some core code, which I am hoping that your code will turn into for
> > other devices of the same type, right?)
> 
> The most important chunk of likely common code I can see at the moment
> is the stuff for bodging user page mappings that we got hammered over
> already.  The drivers/infiniband/ tree already has code that does
> something like this, and a few other not-yet-in-tree network drivers
> that support RDMA have similar needs, too.

The RDMA-loving people need to get together and hammer out a proposal
that the network people can laugh at and shoot down all at once :)

Ok, maybe not shoot down, but they do need to get together and come up
with some kind of solution, add-hok implementations in a bunch of
different drivers, in a bunch of different ways is not the proper thing
to do, no matter _how_ different the hardware works at the lower levels.

thanks,

greg k-h