[openib-general] Re: Re: Re: madvise MADV_DONTFORK/MADV_DOFORK

[Michael S. Tsirkin]

Quoting r. Gleb Natapov <glebn at voltaire.com>:
> > > > ibv_reg_mr works fine for sub-page regions. Doesnt it?
> > >
> > > Not really. It gives you the impression that it works by not returning an
> > > error and aligning address and lengths for you. Same case with mmap(). You
> > > can provide nonaligned length and it will not fail.
> > 
> > As far as I know hardware supports non-aligned regions and so does
> > ibv_reg_mr: try to access outside the region and you'll get completion with
> > error.  No? If not, let me know - it should be easy to fix.
>
> Of cause you are right about reg_mr effect in regards to infiniband protocol. 
> I was talked about the effect on VM subsystem. Any real program can't
> ignore this.

It cant? Why does it care?

-- 
Michael S. Tsirkin
Staff Engineer, Mellanox Technologies