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Date: Tue, 5 Dec 2000 01:43:41 -0600
To: Peter.Ronnquist@nokia.com
Cc: linux-kernel@vger.kernel.org
Subject: Re: shared memory, mmap not recommended?
Message-ID: <20001205014340.C6567@cadcamlab.org>
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In-Reply-To: <9524EA4E18D6D2119FEA0008C7C5A006BE4A77@lneis01nok>; from Peter.Ronnquist@nokia.com on Tue, Dec 05, 2000 at 09:36:50AM +0200
From: Peter Samuelson <peter@cadcamlab.org>
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  [Linus]
> > (otherwise I'll just end up disabling shared mmap - I doubt anybody
> > really uses it anyway, but it would be more polite to just support
> > it).

[Peter R?nnquist]
> I was thinking about using mmap for shared mememory in my program,
> but now I am reconsidering.  Is the System V or Posix mechanism for
> shared memory a better(it will be supported in 2.4) choice?

Linus was talking about shared mmap on a file in an smbfs filesystem.
Rather different from what you are talking about.  For regular shared
memory, shared mmap should be OK if you actually need backing store
(i.e. the state you are sharing is persistent).  Often this is not the
case, in which case POSIX shm might be best.

Peter
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