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

[Hal Rosenstock]

On Thu, 2005-01-06 at 05:53, Michael S. Tsirkin wrote:
> Hello, Roland!
> Quoting r. Roland Dreier (roland.list at gmail.com) "Re: [openib-general] Some Missing Features from mthca/user MAD access":
> > > 1. The SM needs the ability to write (set/clear) the 'is_sm' PortInfo
> > > capability mask bit (from user space).
> > 
> > Yes, I'll implement this.
> 
> Didnt Shahar already do this?

Not as far as I know. He was inquiring about this and I don't think he
got to implementing anything.

> Anyway, as a reminder, there are a couple of issues to consider with this:
> 1. there shall, properly, be only one sm at the same time
> 
>    so I think an attempt to set it when its already set
>    shall fail or block.

I would think failing is a better solution for this. That way the second
SM attempting to be started on the port can indicate that there already
is an SM running on the port.

> 2. when sm exits the bit shall be auto-cleared
> 
>    I guess the proper way to do it is on closing the file.

Making sure the bit is cleared is indeed important. It is simple when SM
exits properly. Hopefully something can occur at process cleanup time to
ensure this does happen even in the case where the SM dies. Otherwise a
special utility might be required to turn this off (so an OpenSM can be
restarted (when #1 is implemented)).

-- Hal