[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Removal of unexec support from glibc malloc
From: |
Daniel Colascione |
Subject: |
Re: Removal of unexec support from glibc malloc |
Date: |
Mon, 18 Jan 2016 14:12:21 -0800 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 |
On 01/18/2016 02:10 PM, Philipp Stephani wrote:
>
>
> Daniel Colascione <address@hidden <mailto:address@hidden>> schrieb
> am Mo., 18. Jan. 2016 um 21:05 Uhr:
>
> On 01/18/2016 12:02 PM, Eli Zaretskii wrote:
> >> From: Paul Eggert <address@hidden <mailto:address@hidden>>
> >> Date: Mon, 18 Jan 2016 11:50:31 -0800
> >>
> >> Emacs could live without the current unexec in a semi-portable
> way by doing what
> >> XEmacs does, which is to write out data and mmap it in later
> (sorry, don't know
> >> the details). There are other possibilities, e.g., have unexec
> write out the
> >> state in the form of C files that are compiled and linked in the
> usual way to
> >> build a faster-starting executable (this would be an Emacs API
> change, though).
> >> Any such changes would take some time to hack into something
> reliable and
> >> portable, and so will have to wait until after Emacs 25 is out.
> >
> > There's also what the MS-Windows port does (temacs allocates off a
> > static array), which AFAIK is entirely portable, and doesn't require
> > mmap. See w32heap.c.
> >
>
> It's a portable stopgap, maybe, but a real portable dumper would be
> _much_ better, since then Emacs could be a much safer
> position-independnent executable (as a portable dumper would relocate
> the dump as it loads, since it knows where all the pointers are).
>
>
> I completely agree. Also see the existing bugs
> https://debbugs.gnu.org/cgi/bugreport.cgi?bug=20215 and
> https://debbugs.gnu.org/cgi/bugreport.cgi?bug=20868.
> Does anybody have a rough estimate what would be required to make the
> dumper really portable?
I think it depends on how much we depend on non-lisp malloc-sourced
memory allocations. I honestly don't know.
As long as we're talking about work to do: I'd love for the new portable
dumper to support dumping Emacs multiple times. I've had to put a lot of
effort into my configuration to get Emacs to start in an acceptable
time, and a lot of people tolerate multi-second Emacs startup times.
It'd be nice if we could dump Emacs after loading user customizations.
signature.asc
Description: OpenPGP digital signature
- Re: Removal of unexec support from glibc malloc, (continued)
- Re: Removal of unexec support from glibc malloc, Daniel Colascione, 2016/01/18
- Re: Removal of unexec support from glibc malloc, Zack Weinberg, 2016/01/18
- Re: Removal of unexec support from glibc malloc, Daniel Colascione, 2016/01/18
- Re: Removal of unexec support from glibc malloc, Joseph Myers, 2016/01/18
- Re: Removal of unexec support from glibc malloc, Florian Weimer, 2016/01/18
- Re: Removal of unexec support from glibc malloc, Paul Eggert, 2016/01/18
- Re: Removal of unexec support from glibc malloc, Daniel Colascione, 2016/01/18
- Re: Removal of unexec support from glibc malloc, Eli Zaretskii, 2016/01/18
- Re: Removal of unexec support from glibc malloc, Daniel Colascione, 2016/01/18
- Re: Removal of unexec support from glibc malloc, Philipp Stephani, 2016/01/18
- Re: Removal of unexec support from glibc malloc,
Daniel Colascione <=
- Re: Removal of unexec support from glibc malloc, Óscar Fuentes, 2016/01/18
- Re: Removal of unexec support from glibc malloc, Stefan Monnier, 2016/01/23
- Re: Removal of unexec support from glibc malloc, Wolfgang Jenkner, 2016/01/18
- Re: Removal of unexec support from glibc malloc, Eli Zaretskii, 2016/01/18
- Re: Removal of unexec support from glibc malloc, Wolfgang Jenkner, 2016/01/18
- Re: Removal of unexec support from glibc malloc, Paul Eggert, 2016/01/18
- Re: Removal of unexec support from glibc malloc, Florian Weimer, 2016/01/18
- Re: Removal of unexec support from glibc malloc, Paul Eggert, 2016/01/19
- Re: Removal of unexec support from glibc malloc, Florian Weimer, 2016/01/19
- Re: Removal of unexec support from glibc malloc, Florian Weimer, 2016/01/19