Re: Preview: portable dumper

[Daniel Colascione]

On 12/01/2016 09:26 AM, Eli Zaretskii wrote:
> > Cc: address@hidden, address@hidden, address@hidden
> > From: Paul Eggert <address@hidden>
> > Date: Thu, 1 Dec 2016 01:16:17 -0800
> >
> >     Emacs never worked on that platform
> >
> > Sure it did. Emacs worked until FreeBSD 11, when the arm64 port modernized its 
> > memory-management implementation.
>
> From https://debbugs.gnu.org/cgi/bugreport.cgi?bug=24892#104
>
>   Ed Maste wrote:
>   > arm64 support was first available in a release in FreeBSD 11.0, without 
> sbrk, and sbrk never existed on the stable/11 branch.
>
>   Thanks, I didn't know that. So Emacs has never worked in this environment.
>
> Doesn't that mean Emacs on arm64 was never available before FreeBSD
> 11, and sbrk never existed on FreeBSD/arm64?
>
> >     they removed a certain library function, which happens to be called by 
> > unexec.
> >
> > This was no accident. They removed it because it was producing bogus values, 
> > and it didn't reflect how FreeBSD actually allocates memory.
>
> And they are thinking on bringing it back, see

They shouldn't bring it back. Reserving a single region in a process as 
"the heap" and doling out parts of it via mmap is an inflexible 
allocation policy. mmap ought to be the only way to get memory from the 
system.