[openib-general] Some Missing Features from mthca/user MAD access

[Michael S. Tsirkin]

Hello!
Quoting r. Hal Rosenstock (halr at voltaire.com) "Re: [openib-general] Some Missing Features from mthca/user MAD access":
> On Thu, 2005-01-06 at 11:01, Roland Dreier wrote:
> > > The simplest approach I think is, keep some file open, when its closed
> > > (which happends automatically when the process dies) clean the is_sm bit.
> > 
> > This does seem to be the simplest approach.  However, there are two issues
> > I'm still trying to figure out:
> > 
> >  - Where should the file be?  Do we really want to create a bunch of issm
> >    files in /dev that only support open() and close()?  I can't think
> > of anything
> >    better, though.

I wander if sysfs can be used for this somehow.

> 
> There may be other is_xxx files too at some point.

It *is* possible to reuse the umad files for this.
Pass command either with an ioctl, or write/read to a special
offset (force opensm to always access offset 0),
or reuse some flag for open (like O_SYNC ?) ... 
Ugh :) .

MST