Hello! Quoting r. Hal Rosenstock ([EMAIL PROTECTED]) "Re: [openib-general] Some Missing Features from mthca/user MAD access": > On Thu, 2005-01-06 at 05:53, Michael S. Tsirkin wrote: > > Hello, Roland! > > Quoting r. Roland Dreier ([EMAIL PROTECTED]) "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.
What about writing 1 to a special file for this, and looking at O_NONBLOCK to decide what to do (block or fail)? For symmetry, reading will let you know if is_sm is set. > > 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 Ugh. 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. MST _______________________________________________ openib-general mailing list openib-general@openib.org http://openib.org/mailman/listinfo/openib-general To unsubscribe, please visit http://openib.org/mailman/listinfo/openib-general