Re: RFC: ABI support for special memory area

[Florian Weimer <fweimer@redhat.com>]

On 02/28/2017 06:03 PM, H.J. Lu wrote:
> On Tue, Feb 28, 2017 at 8:19 AM, Carlos O'Donell <carlos@redhat.com> wrote:
> > On 02/23/2017 09:59 PM, H.J. Lu wrote:
> > > > Why does it run _after_ all shared objects and the executable file are loaded?
> > >
> > > Since __gnu_mbind_setup may call any external functions, it can only
> > > be done after everything is loaded and relocated.
> >
> > Who defines this function?
>
> Platform vendor with special memory support should provide such function.
>
> > Where is it implemented?
>
> We are working on libmbind to implement it.

That's backwards.  Either we need to merge libmbind in to glibc, or this 
should be something provided by the kernel vDSO.

We certainly don't want to repeat the mistake with the unwinder and 
libgcc_s.

> > Why can't this be run in a constructor? Is that too late?
>
> We can use MCDRAM for dynamically allocated memory with
> memkind.  We are looking for a user-friendly way to use MCDRAM
> for normal data variables.

Is it really necessary to avoid the pointer indirection?

Thanks,
Florian