Re: [HACKERS] mmap and MAP_ANON - Mailing list pgsql-hackers

From ocie@paracel.com
Subject Re: [HACKERS] mmap and MAP_ANON
Date
Msg-id 9805122024.AA05253@dolomite.paracel.com
Whole thread Raw
In response to Re: [HACKERS] mmap and MAP_ANON  (Bruce Momjian <maillist@candle.pha.pa.us>)
Responses Re: [HACKERS] mmap and MAP_ANON  (Bruce Momjian <maillist@candle.pha.pa.us>)
List 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.

Ocie

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