This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [PATCH 1/2] Add note on MALLOC_MMAP_* environment variables
- From: Michael Kerrisk <mtk dot manpages at gmail dot com>
- To: DJ Delorie <dj at redhat dot com>
- Cc: Siddhesh Poyarekar <siddhesh at sourceware dot org>, libc-alpha <libc-alpha at sourceware dot org>
- Date: Tue, 11 Oct 2016 08:20:12 +0200
- Subject: Re: [PATCH 1/2] Add note on MALLOC_MMAP_* environment variables
- Authentication-results: sourceware.org; auth=none
- References: <1476120388-26662-1-git-send-email-siddhesh@sourceware.org> <xna8ecw1la.fsf@greed.delorie.com>
On Mon, Oct 10, 2016 at 7:33 PM, DJ Delorie <dj@redhat.com> wrote:
>
> These variables all end with "_", most likely the original intention is
> that they are not official and may be removed or changed at any time.
>
> By making them official, we lock in that ABI. Is that your intention?
I think the notion that because one does not document something, it's
not an official part of the ABI is at best highly dubious. Especially
when so many "official" parts of the ABI are also not documented.
The only way that documentation might be able to help in such
situations is where pieces are clearly and loudly documented right
from the beginning, in the official documentation, as "not supported,
may disappear at any moment in the future, use at your own risk", but
even then people are likely to ignore the documentation or be unaware
of it.
And in any case, these environment vars have long been documented in
various "unofficial" places including (since 2012)
http://man7.org/linux/man-pages/man3/mallopt.3.html
Cheers,
Michael