Date: Sat, 28 Nov 2009 21:13:48 +1100 From: Andrew MacIntyre <andymac@bullseye.apana.org.au> To: FreeBSD Hackers <freebsd-hackers@FreeBSD.org> Subject: Re: heap limits: mmap(2) vs. break(2) on i386 Message-ID: <4B10F7DC.1080408@bullseye.andymac.org> In-Reply-To: <4B10896E.3080201@sippysoft.com> References: <4B1041EB.9020109@sippysoft.com> <4B1059CA.6040605@FreeBSD.org> <4B10687D.3050209@sippysoft.com> <4B107D29.5030307@FreeBSD.org> <4B10896E.3080201@sippysoft.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Maxim Sobolev wrote:
> Jason Evans wrote:
>> I would set MAXDSIZ to 0, so that the maximum amount of memory is
>> available for mapping shared libraries and files, and allocating via
>> malloc. This may cause problems with a couple of ports that implement
>> their own memory allocators based on sbrk, but otherwise it should be
>> all good. You might also set /etc/malloc.conf to 'd' in order to
>> disable the sbrk calls.
>
> I see, thank you for the explanation. One of the problem that we are
> having is that we use a lot of interpreted languages in our environment
> (python, php etc), and most of those implement their own memory
> allocators, some of which rely on sbrk(2) unfortunately. I believe
> that's where that 2GB limit of ours comes from - one of our Python
> applications is very memory hungry and we had to bump that limit to
> allow it sufficient room.
While Python has its own allocator, it relies on the platform malloc()
rather than sbrk(), and therefore Jason's suggestion to use '-d' in
/etc/malloc.conf should be effective for it.
--
-------------------------------------------------------------------------
Andrew I MacIntyre "These thoughts are mine alone..."
E-mail: andymac@bullseye.apana.org.au (pref) | Snail: PO Box 370
andymac@pcug.org.au (alt) | Belconnen ACT 2616
Web: http://www.andymac.org/ | Australia
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4B10F7DC.1080408>