[openib-general] Re: ibv_reg_mr/ memory locking

[Roland Dreier]

    Michael> Are you aware of the fact that mlock wont always be
    Michael> sufficient for this (notably COW)?  And, pages may be, or
    Michael> become, COW, often without the user knowing.

Yes, in fact I think I was the one who originally debugged this.
However I consider stuff like perfect fork() support a second-order
issue.  Most likely we will need a new VM operation that combines
mlock and setting VM_DONTCOPY atomically, but I would hold off on that
until we have a better understanding of the problems and solutions.

    Michael> Some people do care about it
    Michael> http://kerneltrap.org/node/4540 I dont know how
    Michael> reasonable it is to make this unfixable by design.

This is all pretty encapsulated and can be ripped out later.  Although
if there are better ideas now, please bring them out...

 - R.