Re: [HACKERS] mmap and MAP_ANON
Bruce Momjian <maillist@candle.pha.pa.us>
From: Bruce Momjian <maillist@candle.pha.pa.us>
To: ocie@paracel.com
Cc: hackers@postgreSQL.org
Date: 1998-05-12T21:17:12Z
Lists: pgsql-hackers
> > Bruce Momjian wrote: > > > > > > > > Bruce Momjian wrote: > > > > > > > > Would people tell me what platforms do NOT support the MAP_ANON flag to > > > > the mmap() system call? You should find it in the mmap() manual page. > > > > > > Doesn't seem to appear in Linux (2.0.30 kernel). As another poster > > > commented, /dev/zero can be mapped for anonymous memory. > > > > > > > OK, who doesn't have /dev/zero? > > I have been playing around with mmap on Linux. I have been unable to > mmap /dev/zero or to use MAP_ANON in conjunction with MAP_SHARED. > There is no problem sharing memory when a real file is used. > Solaris-sparc seems to have no trouble sharing memory mapped from > /dev/zero. Very strange. And very bad. We have to have a 100% usable solution, or have some if ANON code, else shared memory. -- Bruce Momjian | 830 Blythe Avenue maillist@candle.pha.pa.us | Drexel Hill, Pennsylvania 19026 + If your life is a hard drive, | (610) 353-9879(w) + Christ can be your backup. | (610) 853-3000(h)