Path: utzoo!attcan!uunet!mcsun!tuvie!brock
From: brock@tuvie (Inst.f.Prakt.Info 1802)
Newsgroups: comp.sys.apollo
Subject: malloc(3), diskspace, fix
Keywords: malloc mmap ms_$mapl
Message-ID: <1926@tuvie>
Date: 26 Oct 90 14:40:02 GMT
Organization: TU Vienna EDP-Center, Vienna, AUSTRIA
Lines: 25

Starting from SR10 malloc reserved all space on disk immediately. Many programs
didn't run anymore. This was the starting point of UNIX-bug2bug compatibility.
There are, however, fixes I found par hazard, I haven't seen them here,
probably You know this already:

1) reimplement malloc with ms_$crtemp etc. (see ms_$intro) 

2) <hopefully more UNIX-ish>:              (man mmap)
   use mmap to create an anonymous object

Both have quite similar nice behaviour.

On HP9000 300/800 Release 7.0 there is no mmap or any similar item, 
therefore ... :-( I think that onelevel storage is not a word known to
HP-UX.

SUN seems to prepare allocation on demand, since the /usr/include/sys/mman.h
defines already ,,not yet implemented flags'' e.g. MAP_NORESERVE for:
,,don't reserve needed swap area''. (SPARC, 4.1 #1)

Does anybody know if mmap will remain, (ms$crtemp will die indeed--sic)
and if it will remain with it's disk-space-saving behaviour?


Ulrich Neumerkel  ulrich@vip.UUCP ulrich@vip.at