[ofa-general] Re: IsSMdisabled and user_mad.c

[Roland Dreier]

 > > I guess it's OK, although I would also like to know how you plan to
 > > handle the interaction between IsSM and IsSMDisabled -- eg what if a
 > > process opens issm0 and then another process tries to open
 > > issmdisabled0?  Or conversely if issmdisabled0 is open, what happens
 > > when someone opens issm0?
 > 
 > I would think those are error cases. Does that make sense ? If so, what
 > error makes most sense ? EINVAL or something else ?

That's not really in keeping with the current interface.  Right now if
one process opens issm0 and then a second process tries to open, the
second process blocks until the first one closes the file.  Would it
make more sense to make the issmdisabled interface work in a similar
way, i.e. only one of issm and issmdisabled can be open at any time,
and an attempt to open both would block the second attempt?