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From: "John S. Dyson" <toor@dyson.iquest.net>
Message-Id: <199708310700.CAA05227@dyson.iquest.net>
Subject: Re: SHM limits and probs in 2.1.7.1
In-Reply-To: <Pine.BSF.3.96.970830231704.664h-100000@localhost> from Doug White at "Aug 30, 97 11:17:57 pm"
To: dwhite@resnet.uoregon.edu
Date: Sun, 31 Aug 1997 02:00:26 -0500 (EST)
Cc: nordwick@scheme.xcf.berkeley.edu, freebsd-questions@FreeBSD.ORG
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Doug White said:
> On 27 Aug 1997, Jason Alan Nordwick wrote:
> 
> > 
> > I am having problem with shm.  Is there a limit to the amount
> > that can be mapped into my process space ?
> 
> yes; these are usually set by the shell.  try `ulimit' to unlock these
> limits.
> 
> There are some constants in the kernel too.  I don't know if the 2.1.7.1
> LINT had them in there though.
> 
Note that earlier versions of the SHM code had some architectural problems,
that limited the total system-wide amount available.  The code mapped the
shared regions into the kernel, and the amount of KVA (Kernel Virtual Address)
space is limited.

Recent versions of the SHM code in the FreeBSD kernel have no such limitation,
and are fully pageable.

John